It's actually really good that he's already started eating a little on his own, and since he's eating and drinking then he should start pooping and peeing soon as well. It's pretty normal for rabbits not to poop much right after the surgery, and once they do start pooping, it may be smaller than usual or even a little soft at first(but not diarrhea), and should get back to normal in the first day or two.
Surgical glue is ok. That's how they do it here too- sutures on the inside and glue on the outside, to hopefully minimize the rabbit wanting to chew at the incision. You do want to check the incision twice a day, to make sure it doesn't get red and infected, and that your rabbit isn't trying to chew at the incision at all. There isn't any need to wash the incision site. it's sealed with the glue and should be clean and sterile. You don't want to be putting anything on the incision that is going to draw your rabbits interest to it and may get him started chewing at it.
Normally here in the US, they don't automatically give antibiotics after a neuter surgery usually(though some vets might), but with you being in a different country and the vet also suggesting it, it might be a good idea to just go ahead and let him have it, if it will help prevent the possibility of an infection starting. Enrofloxacin is considered a pretty safe antibiotic for rabbits, and because it is injected, it is less likely to cause stomach upset with your rabbit, so you shouldn't need to use the bene bac.
I'm glad he's already eating and doing pretty good. Getting them to start eating after a surgery, is always the most nerve racking part for me.
I don't know if the vet mentioned this, but your boy bun can still be fertile til 4-6 weeks after the surgery.
