The information desk at the bus station has a book that lists all the hotels within the free zone and the numbers of the bus lines that run to them. Then you can wait at the right bay, or if there are several bus lines that go to your hotel and they use more than one bay, position yourself at a spot where you can see which comes first. (You don't want to board a bus that will go east on Bath Road when your hotel is west.) It's much easier coming back - just go to the bus stop on the opposite side of the road from where you got off the first one, and board the first bus that comes along.