I also pre-wash with Retayne, I feel it's an extra bit of 'insurance' against a bleed. I do not wash fabrics that I'm looking to get the drawn up crinkly look of a vintage quilt as in muslin and 1930s repros but I do put the Retayne in the wash when I finally do wash the whole thing. I am careful not to use vibrant reds in these quilts as I've seen too many reds bleed all over.
I find it interesting so many antique quilts never seem to show signs of bleeding, but then I've only seen examples in museums that were made as 'show' quilts, not utilitarian, and may never have been intended to be washed.