[dano]

The two-way-sync is between the website and the phone. However, it is my understanding that you can view the website information after he upload its. If the two-way-sync is on his iPhone he should be able to send his information back and forth. I don't know exactly how it works, but there are several users using the iPhone, iTouch and the iPad in unison.

Are you using the "Sync All Logs" under the "Settings" pull down?

Are all the apple products (iPhones in your case) in one name with iTunes? If they are, then iTunes knows that you purchased the two-way-sync and you can purchase it again, on your iPhone, and you won't be charge for the second installation. This I know will give you access to all data, via the web.

Another option is to check the website, since the data is there after he uploads it. It may not be the best option, I am just thinking out loud.