Just 1 apple ID from what I have asked. From chatting with him he setup the second iPhone with the @shaw email address and then after the first full sync, this is when things started to go haywire.
I found this article which indicates using multiple devices but 1 apple ID should work (seems like a possible license violation to me but who knows)
http://gigaom.com/apple/itunes-101-m...tunes-account/