To me fiber arts could be a weaving,almost anything that would have fibers. In art classes in college you could do all sorts of things to hold fibers together so that they could hang in a artistic expression; you absolutely could NOT sew the fibers into a construction that the professors could recognize as being anything remotely resembling a quilt. The art world does not recognize any connection at all between fiber arts and quilting. A fiber art installation seldom has fabric, it would more often have yarn. The only connection I can think of between fiber art and art quilts is they neither one keep anyone warm, both being hung and displayed. That's really a slight connection.
Fiber arts is usually considered an art, quilting is a craft.