One of my cats and my rabbit have a relationship. LOL (Jenny, I liked the way you put that, it made me laugh.)
Anyway, my cat Smokey is like 14 lbs of crazy. Ellie is like 4 lbs of wacko. They love each other. Smokey lays in the floor in the kitchen and Ellie runs around her. Smokey, halfheartedly puts a paw out towards Ellie as she runs passed her. Then Ellie comes and puts her head under Smokey's face to be groomed, Smokey grooms her. Then Ellie grooms Smokey back. Its really cute to see. Ellie doesn't have that relationship with the other cats. The other cats tolerate her, but they don't love on her like Smokey does.
Ellie has been known to pull cat fur to make a nest though, so maybe thats why the other cats don't like her as much as Smokey.
Also, Ellie and my oldest cat fight over a box all the time. The cat thinks its hers and it was really for Ellie, but how do you say no to a 13 year old cat? I don't, so when she gets out Ellie gets in and digs. haha.
Like Jenny said though, you'll want to watch out for the cat scratching and biting your bun. Cats carry some nasty bacteria in their mouths and under their claws. Also, sometimes rabbits lose eyes to cat scratches. (I think Shya?) And sometimes the wounds get so infected that the rabbits don't make it. Or the rabbits contract something from the cats claws or mouth and that kills them. Not to totally scare you, but there is risk when you have cats and rabbits together. I would always monitor them when they're playing. Maybe you could help teach the kitten to not play so rough.