Hi there, welcome!
First of all don’t panic! It’s very normal for there to be little spats and fights during the bonding process. It’s important to try to prevent them, but it’s very hard to be perfect in my experience. If no bunny was injured, it’s ok to keep going with the process. If a bunny got a bad bite or an injury that needs medical attention, then you’ll want to pause bonding and let them heal and calm down. I’m guessing yours are fine from what you described, but you should check them over for injuries.
My sense is that the living room wasn’t neutral enough, so moving from the bathtub to the living room set things off a bit.
I wouldn’t worry about not letting Twix free-roam. For now I would start doing side-swaps every other day or so (leave their litter pans in place so the other rabbit’s dirty litter is there for at least a day or so). Ignoring each other is not a bad thing either, it’s better than aggression. 🙂
Since you barely started and didn’t do much pre-bonding, I would pause sessions for now and do a couple weeks of just side swaps with them living side by side as neighbors. You can give them alternate free-roam of the room for exercise, just be very sure they cant nip each other through the fence or jump over their pen walls.
Then I would either go back to the bathtub (or bathroom floor), or find a brand new neutral space, ideally somewhere out of smell range of their pens. I have a suspicion things will be much calmer after some pre-bonding time.
It sounds like things were going very well at first and you just moved a bit too quickly with changing the location, but little spats also tend to happen in nearly all bondings. A good rule of thumb is that if things are going well, don’t change anything except extend the time they are together. When you get to the point where they are spending several hours together happily a few days in a row, then you can start going for very long sessions. Or, if you need to move them to a new space, make sure it’s as neutral or more neutral than the current space.
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The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.