Not always, but sometimes. Often you can tell if there is potential there, but even that is not reliable when they bunnies get to know each other.
You would be looking for things like grooming, relaxed manner, lying together. However, that can all be there at the start and then dissipate, or you might have a bit of angst at the start and then things turn out well very quickly.
ETA- I wouldn't count myself as experienced as such, btu have done more than my fair share of bonding I reckon.