I don't think the Acolytes are nomadic. I think they just follow most of the Air Nomad's traditions and culture. I don't really know if the original Air Nomads were actually nomadic. We were never given an indiction that they were nomads besides their name and Air being the element of freedom
However, I do have a headcanon that the Air Nomads were actual nomads and that the Air Temples were like, for lack of better comparisions, truck stops for the traveling airbenders. And that Airbenders are raised at the temples then are set free to roam after they're 18.
Well, I think that it would be harder for a non-bender to be a nomad because I'd open you up to be mugged more easily and it would take a very long time to travel. However, I guess it's possible they're nomadic as well. But we haven't seen any acolytes outside of the Air Temples yet.
Well I really don't think they're nomadic because in season two when Tenzin and company arrived at one of the temples they were welcomed with gives not just for their arrival but because of the birth of their last child and I don't remember any such reception happening at Air Temple Island for the occasion nor it ever being mentioned of the great gathering of the Air Acolytes. Also unless they are using current transportation methods it would be really expensive and difficult to do this kind of lifestyle. Also the only indication we were ever given that Air Nomads were nomadic was Aang's many friends around the world before the War, he could have only made them if he traveled to those places. I think Air Acolyte's main task is to maintain the temples and be teachers to others like them and maybe any future airbending descendent of Aang before Harmonic Convergence of course!
It would not be expensive if they had bison. Of the flying verritey that is.
I don't even think we have seen an Acolyte with one by themselves nor with company yet either. I mean Aang's friends at lease once did take control of Appa, but maybe out of respect to Air Nomad culture the Air Acolytes don't ride them to not seem equal to the airbenders as they are not even benders themselves.
Desperate times call for mesures equally as desperate.
Maybe so, however a lifestyle choice doesn't seem like it needs this until such a time as desperation. Since I think that at lease some sandbenders practice a nomadic lifestyle, yet they have those boats that sail on sand I could also guess other animals could be used like those ostrich-horses that we have yet to see in the "Legend of Korra". (EDIT: I looked it up they have appered, but only in a flashback in the first book and a Mover in the second)
It was desperate times, there was only Aang when it was founded.
Well yeah he could teach others to carry on the culture, however as seen in the "Promise" comic book trilogy, Aang was mad that the "Official Avatar Aang Fan Club" would dare imitate the tattoos of the Air Nomads, maybe that was another thing he didn't find appropriate for them to ride Sky-bison or maybe it was the Acolytes from this experience that didn't think it would be in the spirit of not being Air Nomads.