There’s no reason why you can’t bond two different breeds of bunnies. The only concern is that the smaller one could get seriously hurt in any bonding scuffles or fights that might occur. But, with any bonding you should be watching closely to prevent fights before they happen, so it shouldn’t be especially different to regular bonding.

I’ve been bonding my 1kg rabbit to a 2kg rabbit, and while I have been concerned that the smaller could get hurt, I would have been intervening in the same way regardless of the size difference. I don’t think either of them is particularly aware of it.

You should do some prebonding for at least a month before you start bonding them (and obviously they need to be spayed and neutered first). This helps them get used to each others scent, and you should be able to tell how they’ll react to each other from prebonding too. Prebonding is swapping food bowls, teddies, litter trays, and even the bunnies themselves between hutches. You can start prebonding now if you want, but if you’re waiting to neuter I don’t think there’s a rush.

Shown, Clover, an unspayed 3 year old American Chinchilla, 15 lbs, and Dawn, an unspayed Netherland Dwarf Black Otter, 2 lbs and change.  Best of buddies.  Took about a week, and they’re thick as thieves now.

However, Clover is a very unusual bunny, and their bonding took less time than it should have.  And still, there was some chasing, some hair pulling, the usual dominance games.  We still have our once a month episodes where Dawn gets it into her little melon that she can dominate Clover, and humps her head until Clover decides she’s had enough and head flips Dawn across the room.  Then it’s back to being cuddle buddies.

Take your time, go slow, and watch them like hawks when they are finally in the open together.   Don’t try and integrate them until well after their surgery, and, as I saw on another thread, hormones can still spike for a while after the surgeries.  And good luck.   Bonded bunny buddies make a home fun.

Each rabbit needs about 18sqft each. Their hutch can be smaller as long as they have an attached run space that is large enough.