I have not kept up to date with your buns. Are they both neutered and vaccinated?
If they are not I woud suggest getting these done first, waiting 2 weeks in between each one. Then after 2 weeks you should be ok for getting on with bonding them together.
If they are both neutered and vaccinated then you can start as soon as you want. I would suggest leaving it until you have at least 48 hours free so that you can start and keep going without the need to separate them.
If you are bonding them now then they shouldnt be separated. Humping, chasing and nipping are all to be expected in the early days and as long so neither bun is being overly aggressive you are best to leave them to sort it out between themselves. Are they in the hutch now or inside? You should really supervise them over night if they are still bonding.
I have not kept up to date with your buns. Are they both neutered and vaccinated?
If they are not I woud suggest getting these done first, waiting 2 weeks in between each one. Then after 2 weeks you should be ok for getting on with bonding them together.
If they are both neutered and vaccinated then you can start as soon as you want. I would suggest leaving it until you have at least 48 hours free so that you can start and keep going without the need to separate them.