Previously I took my boy with my girl to the vets but brought him back, then took him later to collect her. They didn't want the risk of him jumping on her during recovery but they were happy for me to collect her early with some critical care food, if she didn't start eating on her own. She did eat after an hour and i think it helped having him there to encourage her.
I must admit now i prefer to get my rabbits neutered before bonding, just in case the worst happens, although I have had 6 females and 8 males neutered over the years and never lost one under GA!