I found the button in settings, but my iPhone says the sync will resume when it finds my computer.
They're both on the school network, but my understanding is that connections between devices isn't allowed on the school network.
The weird part is, even if I have my computer set up an ad-hoc network and have my iPhone join it, they still don't see each other. Normally using ad-hoc works around these kinds of issues... I've managed to get my wireless printer and my laptop to connect to my iMac by doing it.
So maybe it's not the network that's causing the issue?