I have always taken a bonded pair together, unless there is a specific reason not to do so. My vet will separate temporarily while bunny recovers from the anaesthetic but they do put them back together again pretty soon. The nurses are keeping a close eye on their post-op recovery anyway so can see if a bun is starting to perk up and munch. In general, I think there is s risk to the bond even with a day apart, as they rely so heavily on their sense of smell and that can be disrupted by all the strong vet smells. In many cases it may be fine but by the time you find out whether it is or not, it could be too late to do anything about it! Personally I would always advocate taking the pair together unless there is a specific reason not to, such as a very seriously ill bunny who is likely to need isolation and intensive nursing, or if the healthy companion bunny is particularly anxious and for whom a day at the vets with partner is likely to cause more anxiety than a day home alone without partner.
