Fixed male and female rabbits can bond. I believe especially if they are fixed, it pretty much comes down to the individual rabbits themselves. All my rabbits were fixed, since they're pets. I've had two males together who were best friends once bonded. Right now I have a male and female who get along great. They bonded pretty quickly with little issues. Lion, my male, can be a pretty big jerk so he could be difficult and mean to Pumpkin my girl, but in the end they became really great buddies. This just shows how different personalities can help or hinder the bonding process.
As I said, each rabbit is different, and so there are chances that some pairs won't ever bond, or some will be way harder and others will be way easier. Once your female bun has recovered from her spaying, which would also give them time to sniff and see each other, I see no reason not to start bonding.
I've never had two females together so I can't speak from experience, but as I said before, if they are fixed that reduces a ton of issues, so unless someone corrects me, I don't see why you wouldn't be able to get one.
