Im in the same situation as you. As the CRU and the IRU of a corporate account, I cant take my wife with me in line to purchase a 2nd iPhone on a family plan. We're both doctors and im already burning Friday to get the phones and she's in surgery all day. I called my account specialist with ATT premier and explained the situation, he annotated in my account what I was telling him and under the special instructions portion of your account, he allotted permission for me to purchase 2 iPhones on my account and my wife's account. He told me if the CSR or the store manager has problems with it, to refer to account notes, and furthermore, if they still will not honor it, for them to call him, my account specialist or Corporate. Hope this helps.
Sleepydoc🙂