Astral Domain

On the Ask Robert section, ariesr asks whether Robert thinks other planets (or universal habitats) would have their own domains, that reflect their own environments & lifeforms:
viewtopic.php?f=28&t=11185
If I were answering the question, my guess would be that their RTZ would be the domain that most likely were inhabited by their lifeforms, as they know, because it is the closest to the material according to most theoretical models. Some would say the etheric, but I consider them degrees of the same.
So it would seem to me the RTZ would be the answer for lifeforms that inhabit planets and/or satellites, that is, threedimensional spacetime habitats. As to other types of possible habitats, I would think that's what the astral planes are.
Of course, this is only a guess on my part.