Do you get the discount of the iPhone data plan and text messaging or just the voice plan?
I used to get our FAN discount on the iPhone data plan but it stopped at some point.
It depends on your company's contract with AT&T, but I noticed that I had a discount on my iPhone 4 2GB data feature; however, I needed to use hotspot one time, and when I tried to go back, I could only choose 3GB, and that feature didn't get the FAN discount
Fortunately, when I got my iPhone 5, that got the FAN discount again
The FAN discount also applies to the voice plan, but not to messaging, but again that could depend on your company's contract with AT&T.