It’s good that you have them separated. Rabbits can severely injure each other when they fight. Fighting and being injured can also make them hold a grudge, which can make bonding very difficult.
They evidently had a sudden surge of hormones due to puberty, which is why the fighting started. It doesn’t matter if rabbits are siblings and have grown up together. When the hormones come flooding in, they cannot be kept together.
You will need to wait around a month after their surgeries before attempting their permanent bond. They only had a temporary baby bond previously. It can take a month or more for the hormones to abate, so they shouldn’t even be let out for play and exercise together. You can keep them in the same room, just don’t let them have any physical access to each other, not even through the cage bars.
After a month or so, you can begin the bonding. I’ve had great success using an x-pen. My husband and I get in with the rabbits, to stop any fighting (which we’ve never had) or to stop excessive humping. But there are many methods.
Here are 2 good articles:
http://rabbit.org/faq-bonding-multiple-rabbits/
https://binkybunny.com/BUNNYINFO/tabid/53/CategoryID/9/PID/940/Default.aspx