the batting you use dictates the amount of necessary quilting- but also you want balance- for it to look good and hang/drape properly. as long as the design is balanced and meets the minimum required (dictated by the batting choice) you can quilt it any way you want-
and if it's a wall hanging which will never be laundered you can ignore the batting recommendations- but if it will be laundered-the minimum required by the batting choice is very important for a happy outcome