A well basted quilt or Hobbs 80/20 fusible batt would have helped avoid puckers on the back. To fix the puckers you have, you would need to unpick the lines of quilting and start over. I would press the extra fullness into a dart and hand stitch it closed with an invisible ladder stitch. You could even hand embroider a little vine along it to further disguise it. Good luck with whatever you decide to do.