I am totally cynical about returning for an assessment to be honest. Rosie's condition is amazing considering how poorly she was and her age etc. And Rosie's initial consultation turned up nothing - no ear infection was visible although vet did appear to do a good inspection. He just commented on the gunk, which he thought best to leave alone and I left with just an increase in pain meds (which I suggested myself). And, sorry to repeat myself, but had I not rang up after the appointment and requested antibiotics "just in case it is an ear-infection", I doubt Rosie would be here today. So I am dubious as to whether there is any point to going back.
As an aside really, I am assuming she had an ear-infection only on the basis of her stunning recovery, which began immediately she started taking them. But the ear-infection is only a guess really taking into account her off balance and swaying symptoms? Is it a fair guess in anyone's opinion?
Ear infections can be hard to confirm without an xray, but gunky ears, headtilt, head-shaking, loss of balance etc are all symptoms. If you're not confident in your vet's ability, I'd recommend changing to one you do trust, whether that's another vet at the practice who has more rabbit experience, or at a different surgery altogether.