What a wonderful idea to turn a wedding dress into a quilt. I wish I had done that.
In Alex Andersen's Neutral Essentials book, there are some beautiful quilts that I think the white fabric from a wedding dress would look stunning. Couple the white with some neutrals, and you'll have something that you'll treasure for many years. Since it will be a special quilt, I would not get hung up that you are mixing fabrics like satin and cotton. Just go for it.
http://www.amazon.com/Neutral-Essent...571204180#noop