Rebonding after vets

Need a little help please. 2 male rabbits around 3 years old. One was neutered when I got them a few months ago. Other one was 'done' last week Was advised by vet to keep rabbit indoors and separated from other one till healed and reintroduce them this weekend.

Put them together in their run today and rabbit who has just had the op chased and humped the other one biting at his fur. At first the other one ran but then stopped and allowed it to happen.

Does this mean they need rebonding again?

I only have outdoor cage which they shared before. I've brought one in again tonight now it's dark and I can no longer supervise them but this isnt a long term solution as it was never the intention to have an indoor rabbit and hes confined to a cage.

Where do I go from here?

He may have been chasing the other bun to reinstate his dominance - as long as there is no fighting keep them together and monitor them closely for a few hours. If this fails you will have to rebond them in neutral territory I'm afraid. Which rabbit was the dominant one before the op - I would suspect it was the entire rabbit, so the neutering will have upset the hierarchy a little. Hope they settle down together again soon.