I say wear what ever the hell you want. Someone may not approve of your choice of garment, or the integration of some outside entity into it, say for instance a Yankees symbol in a Steal Your Face. Who cares? I do things for me, that I like, and ultimately could not care less what anyone else thinks about it. It they do not approve of what I am wearing, that is their problem. I may choose to wear a Gov't Mule shirt to a Furthur show, another person may hate the Mule. Oh well, get over it.
Doesnt matter what you wear, just as long as you are there. One of the nice things about going to a show, is no matter what you are wearing, you fit in and are not judged. The creativity is amazing in this community. Im guilty for wearing a Giants/Stealie.