BOTH! art tends to be lots of people's hobbies---my mother is a commercial artist- managed to raise 6 kids with her art- she also enjoys painting as her hobbie-
there is a difference between an art quilt and a traditional quilt- but i make alot of traditional quilts that people look at and tell me---wow- you are an artist! no reason for there to be a difference-
if a degree will help you further your hobbie why not? same as taking any other classes to further your interest- learn new techniques- color theory---lots of things- if you have time and $$--and the desire- why would it matter if it's to further your hobbie- or just because you have an interest- or make it a career choice??