I wouldn't wrap it. I would just make sure it stays clean(diluted betadine with 4 parts water if cleaning needed, with cotton wool or gauze, don't get in ear), maybe a very light layer of plain neosporin ointment(no added pain relief) applied a couple times a day for several days, then keep an eye on it to make sure it heals normally and a lump(abscess) or infection doesn't form. It's usually good to distract the bun with food or something after applying the ointment, so it's not immediately groomed off. It'll probably take a week to 2 weeks to heal, depending on how deep it went.
This is just what I would do for a minor surface wound. It's not recommended medical advice, nor do I have a medical source to support this info. So up to you what to decide, and know it's always recommended and best to consult with a knowledgeable rabbit vet. And if it's deeper than a surface wound, you should definitely take your bun to the vet. Your bun may need to be on a rabbit safe oral antibiotic.