I just love your colors! The batiks are so vibrant.
If washing and blocking doesn't get rid of your wavy borders, here is a tip that might help for next time. Before you sew your binding on, sew a 1/8-inch ribbon (like the kind you find in the craft or fabric store) down the edge of your quilt. Then add your binding as normal, which will completely hide this ribbon inside your binding. It helps support the edge and keeps it from waving. At least that's supposed to be how it works. I haven't tried this method and am just repeating what I learned at a demo at my local quilt guild. The gal who gave the demonstration places and wins lots of ribbons so I am assuming she knows what she is talking about. Hoep this helps!
~Tiffany