I would not use any poly blends, only Kona or similiar....problem was the silly flannel backing....perhaps find a nice novelty "Americana" print for backing instead of the red flannel......
But first I would try to salvage the original quilt, and I think it can be salvaged. Try Oxyclean and then Synthrapol
the bleeding will stop when it runs out of dye.....
At this time you do not have that much to loose and everything to gain by trying to salvage the original.....