That is called "crocking" -- color rubbing off onto other surfaces due to mechanical abrasion. It's not exactly the same as bleeding, which occurs when the dye is wet.
The ideal would have been to treat the fabric with Retayne when you pre-washed it, then test for both bleeding (dropping a small piece in a glass of water for a half hour or so) and crocking (rubbing against a piece of white fabric). Once the fabric is in the quilt it is too late to treat with Retayne because Retayne would set any unwanted bleeds into other fabrics.
At this point I don't think there is anything that will guarantee this problem will stop. You can try washing with Synthrapol several times after the quilt is finished; that might do the trick. Synthrapol is sold in quilts shops and online; even Amazon has it.
"To prevent serious crocking or dye transfer, make sure to wash the fabric in Synthrapol (available from Dharma Trading Co.) thoroughly; Synthrapol suspends the excess dye in the water and keeps it from going back onto the fabric. This may take 2-3 trips through the washer. " from
http://www.alleycatscratch.com/lotr/...ricDyeing.htm.
It would be safer to take the quilt sandwich apart, remove the red fabric, and then treat it and test it before incorporating back into the quilt.
If you Google crocking dyes, you will find more info.