Hi
I've got five cats and six rabbits and they all seem to get on OK. When I got the last two cats I only let them see the rabbits under supervision initially. If they are all out in the garden together (which doesn't happen very often as trying to catch the bunnies is a nightmare - they usually live in a fenced off yard!) the rabbits chase the cats and the cats just jump up on the fence when they get fed up with the game!
It's quite amusing watching my tiny netherland dwarf chasing my large black and white moggie
I hope your two will get on as bunnies like company.
Lumpy