I think you are very lucky.
Retayne works well to set dye in a single fabric, but I would never advise using it to wash a quilt or quilt top. If a dye bleeds in the wash, Retayne will set the color permanently into every fabric it bleeds into.
For an already-made quilt, it's safer to wash in Synthrapol. Synthrapol suspends unset dye particles in the water so the particles are rinsed away instead of settling into other fabrics.