I just wanted to say, that our vet has prescribed something called Fucidin cream for our buns before- Chalk had a fairly deep cut on her shoulder from a scuffle with Snowy aaaages ago. We were given something called hibiscrub to mix with lukewarm water and clean the wound (this is a safe antiseptic solution), and Fucidin cream to apply directly, thinly. Chalk's cut was healed within a matter of days with this treatment.
I haven't researched the Fucidin much, but just wanted to add that, in case those products are more widely available than US ones, although I believe the Fucidin is prescription-only, i.e you will have to get it from the vets.
I hope the bunny is ok!