AT&T and Apple.com orders

[fenway15]

I'm hoping somebody can help me out here. I ordered a SG 64gb 6+ on 10/16 through apple.com that has a delivery date of 11/14-11/21. The following week I ordered the same phone for another line through AT&T. Here's the crazy part, just a week later (today) I received tracking info and the second 6+ I ordered will be here on Tuesday the 4th! Well my question is can I take this phone and use it for the line that has a 6+ still on order through apple.com? These are both through AT&T next by the way.