They do contain the bridge ID, just like you described. I don’t think there is any other way of getting it to work without configuring it this way.
I have updated Homegear to the latest nighly now as I noticed that one CCU was working fine (which was running a nightly) and the other one which was running stable was causing issues. Let’s see if that helps or makes a difference, maybe it is not an openHAB issue after all.