Thanks, everyone who offered suggestions about the bleed. I tried Tide stain stick, and it faded it a bit, but I could also see more bleeding appear around the edge on the front of the quilt from the wetting. I decided against a full washing because I was afraid of worse bleeding that would come through to the front, and also I was concerned about too much shrinking with the wool batt. That would have been a totally different look than I had planned, and I don't know how it would have affected the total look.
So, I took out some quilting stitches, and used something called Pentel dye sticks, which seem to be very waxy and crayon-like. It then occurred to me that actual crayons might work too, so I added them. Wish I'd thought of that first because the color match was better and the sharper point worked well with the pattern on the backing. Then I used a hot iron to set both and remove the waxy stuff. It's better; it looks like a slightly darker section of the fabric, and doesn't jump out at you like the pink did. But if you look closely you can see something is odd. (There is actually less pink visible in reality than in this picture.)
I was afraid I'd made the wrong choice and was too timid, but just heard from someone with a horror story about trying to remove a bleed with Synthrapol, so I feel better. Next step will be to distract by adding a very elaborate label!
I'll also try to remember that the oil spill is worse.