I would definitely wait until he is neutered, for right now hormones will make it impossible to bond, and all the progress that you make will vanish as soon as he’s neutered, unfortunately. Waiting a few weeks after that even is a good idea too. For, after they are fixed, hormones will still be “floating around”, so it’s always good to wait for those to drain out. 🙂
For when you do start bonding, some of my recommendations would be to do a bit more pre-bonding (cage, litter box, and toy swaps) seeing as your female rabbit is a little scared of him currently, and having a bit more time to get used to his scent may help. 🙂 I’m thinking that the playpen can also work for a semi-neutral territory once you’ve finished in neutral, for when you start bonding sessions. 🙂
Seems to me as though you’ll have an easy bond once the female figures out that he isn’t a threat. 😉 It’s a good thing that you also have their pens next to each other too, that helps a lot when bonding! 😉 You’ll have to send us lots of pictures of them snuggling once they’ve bonded! 😉