If you are an old Powertel customer, you must switch over to the one of the VoiceStream plans to get the expanded calling area. We happened to be in the Voice Stream store and I double checked.
The old Powertel plans don't have the expanded non-roaming area.
We had the 3700 minute Powertel plan with free incoming 1st minute and we switched to the 2500 minute Voice Stream plan. We never use near that many minutes, so I didn't mind giving them up to get the increased area.
Oh, and I noticed your going this weekend. When you call and make the change, it won't take effect till your next billing cycle.