Question:
Are Datacom/AD 15.1 PTFs needed for version 15.0?
No. Datacom version 15.1 PTFs are not applicable to Datacom/AD Version 15.0 nor for Datacom/DB 15.0.
Datacom/DB 15.1 is a separate SMP/E install altogether with different FMIDs.
That is, version 15.1 FMIDs are CA**F10 while the 15.0 FMIDs are CA**F00.