It does depend on the project you are doing and how you plan to quilt it. I use Hobbs 80/20 because I like how it machine quilts. I like polyester for hand quilting because cotton tends to grab my needle and make it more difficult to get small stitches. So how are you planning to quilt it?
The news I have heard about Bamboo batting is that it is expensive and although it is a renewable resource, the production process is not environmentally friendly.