Another reason could be a miscommunication or misunderstanding between them in the fanfic. Perhaps Elena says or does something that Bonnie misinterprets as a betrayal. It could be as simple as Elena making a decision about a supernatural event that Bonnie disagrees with strongly, and this builds up resentment over time until Bonnie hates her.
In some fanfics, Bonnie might hate Elena because of jealousy. Maybe Elena always gets the attention of the male characters they both know, like Stefan or Damon, and Bonnie feels left out or second - rate in comparison.
Well, it could be due to plot - driven reasons in the fanfic. For example, if the writer wants to create some sort of conflict or drama. Bonnie could be made to hate Elena because Elena unknowingly does something that has a negative impact on Bonnie's family or magic. Maybe Elena makes a deal with a dark force that ends up endangering Bonnie's life or her family's safety in the fanfic world.
If you want the clearest chapter reference, go to Chapter 27. Early on, They had spent an entire year gradually inviting a few people.; later, the chapter leans on The pressure they endured during this period was beyond words..
Chapter 34 is the strongest chapter-level answer because it starts from Seeing that the public sentiment wasn't quite right, Su Yinwan felt... and follows through on Now that Lili is misunderstood, they start to kick us while we're down."....
Look to Chapter 52 for the clearest answer. It begins with The village chief and the woman behind him exchanged a glance, "This..., keeps building through might not be a good idea, you guys are still filming, we don't want to..., and lands on And at this point, they might as well try a desperate.
The best chapter pointer here is Chapter 5, "Catching Adultery Personally". It opens with Actually, when Manager Fang saw Jiang Li, he was somewhat surprised. and closes on Recently, he did suspect that his wife was cheating on him, but due to the....
The best chapter pointer here is Chapter 34, "Official Recording!". It opens with Seeing that the public sentiment wasn't quite right, Su Yinwan felt... and closes on Now that Lili is misunderstood, they start to kick us while we're down."....
If you want the clearest chapter reference, go to Chapter 31. Early on, Before Shen Lan had reached the backyard, she already heard the sounds of...; later, the chapter leans on Facing the freshly risen morning sun, she noticed at a glance the girl....
If you want the clearest chapter reference, go to Chapter 36. Early on, But soon, people began to question the authenticity of Jiang Li's bare...; later, the chapter leans on After all, these days, faux bare-faced makeup can be indistinguishable....
The best chapter pointer here is Chapter 18, "Criminal Law stipulates that kidnappers will be imprisoned.". It opens with In the corner, a girl in a black dress sat quietly, holding a glass of... and closes on Hurry home, what is a young lady like you doing running to a place like....
The best chapter pointer here is Chapter 60, "The Human Oil King". It opens with What's with Jiang Yan, treating his own sister Jiang Li like this?" "He... and closes on And in traditional characters?" "What else?.
Chapter 26 is the strongest chapter-level answer because it starts from Shen Lan was bent over processing a large stack of press briefs on her... and follows through on If you think you can use our family connection to have me handle this....