Only in that it contains gay people. And strait people. And bi people. And completely asexual people.

"Gay comic" usually tends to refer to a comic that is about being gay, or about gay people gaying it gayly.

I guess I wouldn't call TG a gay comic, because it isn't really about gay people. It's about people, some of whom might be gay. Usually the people the comic is about are involved in activities not specific to gayness or not-gayness.