To the best of my knowledge if you can select a heatpump in zone 2 (rear zone), you do indeed have a heat pump installed in that zone. There should be a remote sensor in the bedroom area. Mine is located in the bedroom and behind the slide
when the slide is in.
Start off from scratch, turn everyting off.
Set your rear zone to heat pump and a temp setting high enough to force it to cycle on. Leave the front zone off. After 2 minutes you should hear the rear heat pump come on, it will sound just like the rear AC. If no heat then your heat pump is not working. This is all based on a outside temp higher than 32 degrees or so.
If your rear heatpump is not working and you would like to use elctric insted of LP. Set the rear zone fan to stay on all the time. This will do a fair job of distributing heat from the front of the coach to the rear. The downside is that the air out of the ducts will feel cool. This is all based on having a ducted system(all conditioned air out of the same set of vents). IF your rear heat pump is not working a 20 dollar heater from Wallyworld will do some supplementing.
Don't forget your pipes in the basement if the temps get below freezing. Your furnace should provide heat for the basement. On my 05 Dutch star, there is a switch in the dump station area ,to pull more warm air into the basements when the furnace cycles.