To some degree. People generally don't appear in T'A'R unless they're dreamwalkers or by accident, so there's only so much you can learn about a society from the dream. Though maybe not, Amys seemed to be able to pick up on the presense of the BA and Moggy in Tanchico (unless she just thinks all cities are evil because they're built by wetlanders).

Also, since the Sharans are pathological liars to outsiders, I can see why the Aiel don't want anything more to do with them beyond the trade relations they already have.