There are different approaches to bonding. One of the more popular methods involves introducing the rabbits in a small neutral space and then not splitting them unless there is serious fighting. To bond well, they need to sort their pecking order and this is harder to do if they're being separated from time to time.
Chasing, fur pulling and humping are normal. If the rabbits are locked on-fighting, then split them for a few seconds (using a broom not your hands or you'll get bitten) and then release.
If all is going well, I would leave them together provided you can supervise them continuously for at least 48 to 72 hrs. The problems often come in the early hours of the morning, at times when the bunnies are naturally more active so even if it's looking promising now, things can suddenly 'flare up'.