The way I did it was to work in just one space until they were fine, then move to another one. When I moved from the tub to the hallway there was definitely an increase in humping again, but it settled down much faster than it had in the tub as they got used to the new area. After they were up to 4-5 hours in the hallway, I moved them to a cage downstairs – there weren’t any neutral areas on the first floor, so I figured it was time they move in together. I tried to make the cage as neutral as possible though (put it in a different area, changed the stuff around, etc)
My basic philosophy was to do one thing until they were so calm together that it was boring. If I felt I could read a book while they were in the bathtub and I didn’t need to stress them, then it was time to move on somewhere else. Once I was bored with them in the hallway, it was time to move them in together. If they are still having issues in the bathroom I wouldn’t change locations yet, but eventually it’s a good idea to move them around and get them ok together in different areas.
Another thing I learned the hard way is to bond at different times of day. I did it every afternoon, which is when they are most subdued. It was good for the initial bonding, but they had some issues when they moved in together and Hannah got bossy in the early morning. Not that I would’ve done a bonding session at 5am, but I definitely should’ve done one later at night and fed them dinner together.