Yes, it's art. How much time is spent at something before it is considered a hobby? I paint and sew, and have many other interests. I don't know if I'm passionate enough about any of them to considered them a favored hobby. Especially when I read how all consumming hobbies are for some. I wish I was more passionate about something. I think I have the middle age "blues" ...
Quilting is definitely art, and I think it's great you are going to school to learn more about fiber arts!