|“||I don't need the cure to be happy. I only need you.||”|
— Enzo to Bonnie in You Made a Choice to Be Good
Their relationship began in Total Eclipse of the Heart, when Enzo, who was working with Damon to track down the remaining Augustine members, decided that the best way to get Bonnie to help them find Wes was to threaten her boyfriend, Jeremy, with death. This set their relationship off to a rocky and antagonistic start, but they were ultimately able to set aside their dislike of each other to focus on bringing Enzo and many of Bonnie's friends back from the Other Side before its collapse.
In Season Seven, we see the pair in a romantic relationship, but in a flash forward, after Bonnie gets in trouble with the Armory, three years ago, and Enzo stepped up to keep them away from her. Enzo moves Bonnie up in a cabin, and over the years the two began to grow close. Two years later, after their romantic feelings had build up, the two started a romantic relationship and fell in love. After dating for three years, they have been separated due to the Armory's Monster mentally incapacitating him to do the creature's biding (along with Bonnie and Enzo's best friend, Damon). Bonnie, along with their friends, have tried to find and save Enzo and Damon from their mental hijacking by the Armory's unknown and mysterious creature. They are offcially reunited in Coming Home Was a Mistake, after Bonnie managed to get Enzo's humanity back on.
They are known as "Bonenzo" or "Benzo" (unofficially) by fans.
Throughout The Vampire Diaries Series
In I'll Wed You in the Golden Summertime, Enzo is seen knocking at the door of the Salvatore boarding house. Bonnie is the one who answers the door only to close it immediately when she sees him. He holds it open and explains that he's there to visit Lily who must be lonely and hungry. When Bonnie refuses to let him in, he gives her an iPod, asking her to give it to Lily and telling her that it contains loads of songs from the last era she knew.
In Hello, Brother, the season opens up with revealing that it's been months since Bonnie has last been with Enzo. Bonnie and Stefan have been searching for Enzo and Damon for months while knowing that the Armory's monster was mentally controlling them. When they finally get another lead on them, Bonnie refuses to have hope on finding them, but Stefan convinces her to come along for searching their supposed location anyway.
When Bonnie and Stefan do find Enzo and Damon, they tell Bonnie and Stefan that it was a bad idea to find them. When Bonnie refuses to leave because of trying to find Enzo, this puts Stefan and Bonnie in more danger. When Enzo finally appears, Damon puts Bonnie into a chokehold, which she cannot defend herself against being she has no more magic. Stefan finally convinces Damon to let her go. Eventually, Bonnie and Stefan decide to leave, while leaving Enzo and Damon behind. After leaving them, Bonnie exclaims how Enzo was trying to help them with information regarding the creature from the vault. Bonnie now has hope again that she can rescue Enzo and Damon from the Armory's monster's clutches, which is later revealed to be a Siren.In Today Will Be Different, in an another attempt to free Enzo from Sybil's mind control, Bonnie tracks him down and they share a passionate moment together. While in tears, Bonnie begs Enzo to come back to her. However, Enzo promises that he will find his way back to her, but he cannot risk Sybil seeing Bonnie in his mind. Enzo decides to go back to Sybil in an attempt to keep fighting her mind control, also to protect Bonnie from being discovered in his mind by Sybil. Also, earlier in the episode, Enzo pushes the memories of Sarah Nelson (a final family member to the Salvatore family) into his mind when Sybil tries to find what he has to keep control over himself. It was an attempt to protect Bonnie, but it also cost Sarah her life.
In You Decided That I Was Worth Saving, Bonnie is held hostage by Sybil, with Caroline, and Bonnie is forced to rush to Enzo's aid when Sybil forces Damon and Enzo to fight to the death. Bonnie first sends Caroline to defend Enzo against Damon and Stefan, but Enzo and Damon break the necks of Caroline and Stefan and continue to fight brutally. Bonnie finally rushes to Enzo's side and they embrace passionately. Sybil then impatiently states that Enzo must turn his humanity off to save himself and Bonnie. Bonnie begs Enzo in tears not to turn his humanity off, but Enzo says he will do it anyway to save Bonnie and he is certain that Bonnie could bring him back to himself again. So Bonnie is forced to watch Enzo turn his humanity off and he submits himself to Sybil. Sybil then asks Damon to kill Bonnie and asks Enzo if he has a problem with that, to which Enzo responds 'no' twice. In tears, Bonnie is forced to run for her life as Sybil counts down from ten to have Damon kill Bonnie. When Damon catches Bonnie and nearly kills her, Alaric comes in to save her from Damon, Enzo and Sybil.
In An Eternity of Misery, although unseen, it was mentioned that Bonnie took care of Enzo after he was knocked out in front of the Armory, with Sybil. According to Caroline, Bonnie is trying to get Enzo's humanity back on even though Enzo is saying hurtful things to Bonnie while she is trying to get through to him.
In Coming Home Was a Mistake, Bonnie is still trying to get through to Enzo, as she uses a magical object to keep him trapped inside their cabin. After receiving the news about Tyler Lockwood's death this motivates Bonnie to fight harder for Enzo. Skipping out on Tyler's funeral to help Enzo, Bonnie calls Caroline to see if she could give her any advice to help Enzo. Caroline tells Bonnie that facing her fears was how she got her humanity back on. Bonnie has one last talk with Enzo before getting an idea, leaving him at the cabin for a couple of hours. Once she returns Bonnie notice Enzo decorated the cabin like their first New Years Eve night, pretending as though he remembers their date night together. Though Bonnie ignores his banter as she begins to throw gasoline all over the cabin. She tells Enzo she knows his biggest fear is being abandon, so she promises him that she isn't leaving him as she lights the cabin on fire. As the cabin begins to burn down, Enzo lets her know he isn't falling for it, refusing to switch his humanity on still. Bonnie refuses to leave him as the cabin burns down with them inside. The smoke gets in her lungs causing her to collapse onto the floor. After awhile she's no longer responding, Enzo notices and begins to get worried, as he realizes Bonnie could be dying, Enzo finally turns his humanity back on and rescues her.
Once Bonnie awakes outside, she notice Enzo is back but trapped inside the burning cabin. He tells Bonnie it's his time and that she loved him more than anyone, and that it was enough. In a panic Bonnie rushes back inside and burns herself onto the candle to stop the spell. Enzo sees that she's hurt and gets them both of the cabin. He then apologizes for almost killing her, she tells him it's okay, Bonnie lets him know that he's stuck with her forever and that she'll never leave him. They have kiss as their home burns down. Later on the two meet up with the gang to honor Tyler Lockwood.
In Detoured On Some Random Backwoods Path to Hell, Bonnie and Enzo are seen together in Bonnie's bed, after a night of passion. They have a conversation about missing each other while they cuddle on her bed. However, Enzo gets up to grab his phone and suddenly collapses to the floor, cringing in pain from Sybil's siren song as Bonnie worryingly comforts him.
Later on, Bonnie asks Stefan and Matt for help in saving Enzo from whatever is crippling him. Enzo explains that Sybil is mentally incapacitating him as revenge for escaping Sybil's clutches. Enzo is seen lying on a couch in pain and distress with Bonnie by his side as Stefan works to help Enzo by going inside his head. By doing this, Stefan explains that it is only making matters worse for Enzo, but he continues to do so with Alaric's insistence being Damon, Sybil and Seline kidnapped his siphoner twins. After some time, Stefan and the others find where Alaric and Caroline's children are being held. They go to rescue the twins while Bonnie stays with an unconscious Enzo and Matt. Matt insists that Enzo is strong and will get through this, but Bonnie is almost out of hope, until Enzo awakens shortly after Bonnie and Matt's conversation and makes a playful jab that he could kiss them both. Bonnie is overjoyed to see that he broke from Sybil's mental song and hugged him tightly with happy tears following from her eyes.
In We Have History Together, Enzo and Bonnie were not seen in this episode. However, Caroline explains, while on a phone call with Matt, that Enzo and Bonnie were enjoying their vacation together in Paris, France.
- Enzo called Bonnie "little witch" multiple times.
- Michael Malarkey has shown interest in Bonenzo early this year, when Kat Graham had announced Bonnie would be getting a new love interest due to Jeremy leaving.
- The idea for a Bonnie/Enzo pairing began in I'll Wed You in the Golden Summertime when Enzo came to visit Lily at the Salvatore Mansion, where he was met at the door by Bonnie. “Kat [Graham] and Michael [Malarkey] had such … chemistry in that really short scene,” Dries recalls. “We were like, ‘Huh … Let’s explore that relationship.’ Of course, they have no reason to like each other; in the present day, we’ve been telling their hate story. So the whole point is that, when you see them in the future, you’re supposed to be like, ‘Wait, how did they get to there?’ Hopefully it created enough intrigue to keep [fans] guessing.”
- In Days of Future Past, it is revealed that Enzo has been giving Bonnie pills made out of Rayna Cruz's blood and it might be killing her.
- Plec promises fans will get to see how Bonnie and Enzo ended up in love over the missing three years, calling their relationship “lovely” and “beautiful.” This story was explored in Somebody That I Used to Know.
- In One Way or Another, Rayna Cruz confirmed Enzo loves Bonnie.
- As of Somebody That I Used to Know, Enzo is the second man that Bonnie has sex with.
- Bonnie has told Damon that she loves Enzo in Somebody That I Used to Know.
- Julie Plec on Bonnie and Enzo: "In the case of Bonnie and Enzo, we decided to show them in love with each other as a surprise flash-forward, leaving the audience to wonder how in the hell that happened. I really love the idea of them together. Enzo has so much love to give, but has been constantly disappointed by people in his life. Bonnie, always giving so much of herself to others, deserves the kind of love that is unconditional and powerful and selfless. I love them together." 
- Chris Grismer had the Billie Holiday song play out loud for the whole cast and crew while Kat and Michael danced. Everyone was so moved. One of the crew members came up to Holly Brix with tears in her eyes. She wanted Holly to know how much she loved seeing Bonnie get a epic love story.