I haven't tried it yet with 9.1, but I do know that Tableau continues to get more sophisticated with reading of AD groups such as they now recognize "disabled" users and move them into the "unlicensed" user group within all users. I somehow doubt that they do anything special right now for service groups or AD resources, but you could always submit an idea. Ideas
Does it hurt anything to have them imported as part of the AD group? You could always setup a distinct group for this or could always do a custom script.