The AMA is a well-established organisation, going back at least 4 decades. I have not paid attention to it in the last 15 years, so everything here is out of date.
It performs several functions, including organising the highest levels of American motorcycle racing. It also lobbies, but there is a history (again, I have not been paying attention) of the AMA going one way while its membership goes another. It really can't do anything about helmet laws, for example, because there is no consensus among its membership.
If they advertise a service, they provide it. I am sure that they sub-contract roadside asistance to local towing companies, just like the AAA does in outlying regions. If the price is right, go for it.