bladder attitude and altitude

We just took a trip to Birmingham AL from Littleton CO. We put about 3000 miles on the car. I noticed that when we came down from the altitude here in CO, the bladder seemed to allow more gas to be pumped. Could the bladder be affected by altitude? Just something to ponder...Trip was great! This car performed well on long distance and was more comfy than I thought it would be. Our mileage was iffy due to the speed and it was quite windy coming back. We averaged around 46 - 48. We drove 70 - 80 most of the way. Absolutely no problems. We spent approx 140 on fuel. I love my "Flo"