I was only going by this diagram of a typical RV30A-50A Adapter connected to a 50AMP two zone trailer... I don't know if all 30A-50A adapters do this or not. You notice the 30A is strapped to feed both zones on the 50AMP side in this diagram... If this is the case then YES both zones gets powered up and you have to decide what is "on" when using the 30A pedestal source of power otherwise you will trip the pedestal breaker if you are drawing too much current.
If the RV30A-50A-adapter only feeds one zone then only one Air Conditioner will be able to be used...
Just my thoughts
Roy Ken