I believe it is with in your division only... Like I work in central so I can only use then at Central stores..... So if Ralphs and QFC are with in your division you shouldn't have any problems...
What really bothers me is that there's a Central division store kind of close to my house. Like within 30 miles. It's the same distance as the nearby Cincy division stores other than mine (I live in a small town). And the discount won't work in the Central division store.
And they have different prices and products and everything. It's just weird how the divisions are.