Yes Polyester is fine to sew and quilt with. There is great information on this very point , on the Superior Threads web site. He discusses this under the top thread myths here is the quote
" Q. Will polyester thread tear my quilt?
A. This is the most common and worst myth in the quilting world. It is perfectly fine to use polyester thread in your quilt. Some cotton threads are stronger than polyester threads. Most T-shirts are sewn with polyester thread (I called Hanes Company and asked them) and I've never had a seam thread rip through my T shirt. "