Please look over your packaging very carefully. Not all cotton batting is the same. It depends on if it has scrim or not or if it has been needle punched or has any sort of glaze or stabilizer on it.
For example Warm and Natural cotton batting, which does have a scrim and is needle punched can be quilted up to 10" apart, but Mountain Mist Blue ribbon cotton batting must be quilted closely at every 2" and their regular cotton must be quilted at no less than 1/2" intervals! Most poly's can be quilted up to 4 to 6" apart so depending on what you picked up you may have to quilt much more closely than you have in the past.