Your batting choice dictates the amount of quilting required. Some battings need to be quilted every 2" ( pretty dense all over quilting) while others allow up to 10" between quilting lines and everything in between. Read the packaging and choose a batting that allows the distance you want. Warm & natural is one that allows up to 10" between quilting lines and is a popular choice.
The (70/30) batting you stated should state how close you need to quilt. The Hobbs one I have requires every 4". You don't say what brand yours is.