Does it really bother you? Is it really as bad as you think it is? Sometimes we are more critical with our own work. Is this your quilt or for someone else? I had a similar situation just before the holidays but it was my FMQ that left the pucker. It was really big but I didn't have time to fix it before I gave it away. After washing it, the pucker didn't look as bad as before washing. Maybe that will be the same in this case. Personally, I would probably leave it and chalk it up to experience. The only person that will know its there is you. It'll be what makes that quilt unique and special.
NOW, with all that said.....I want to see pics!