With shared producers like Charles Roven and even Christopher Nolan credited as an executive producer on Batman v Superman: Dawn of Justice, after having worked on the seminal "Dark Knight Trilogy," some fans have tried to directly connect the two. However, Roven says they're completely separate (aside from both featuring the DC Comics characters, naturally).
"We really wanted to make a clear demarcation line," Roven told ComingSoon. "Chris [Nolan], Emma [Thomas], and I would talk about how, in his "Dark Knight Trilogy" universe, there are no superheroes," he explained. That's clearly different from the world of Batman v Superman, of course.
"In the universe we created with Man of Steel, there are superheroes. There are aliens. There are metahumans. The character of Batman isn't Christian Bale ten years later, he's different. He's come up a different way." Heck, it even comes down to Martha and Thomas Wayne, Roven said. "His parents, even though they died outside a movie theater, didn't die outside an Opera theater. We thought about those things."
So any fan theories that connect the two are just that - purely fan fun. These are definitely, 100% different worlds.