The one thing i would advise is to introduce gradually. If it is rushed and forced chances are the bonding is not going to work.
You need to continue to keep the buck away from the doe for up to a month after neutering as sperm can survive for up to a month after the op. and therefore, pregnancy is possible still.
I intrduced Dexter and Lily on neutral terriroy, ie. a room neither was familiar with. The resident bun will not then feel threatened by the 'newcomer'. I kept Lily under a cage on the floor. They interacted through the bars and sniffed each other etc and i did this for so long a day, gradually increasing. When they appeared to be used to each other, ie. the foot thumping and running, had stopped i let Lily out with Dexter. Initally i did this for a very short period of time. Lily was quite nervous and Dexter was excited (he was just a month neutered so still had hormones!) so we supervised theyre encounters. Again, you increase the length of time. Eventually they became used to each other.
For a few months Dexter and Lily slept in sepearte cages. I was worried if there was a fight one, or both, could get seriously injured. They now live in the same house and love each other so much!
I only have the two so cant comment on additonal bunnies.
Let us know how you get on and good luck!!!