While every Windows Phone 8 has a Wallet Hub, not all support NFC transactions. The easiest way to check and see if your phone supports NFC transactions is to go to your Wallet settings. In Wallet, tap More More icon, and then tap Settings+PIN. If you don't see an option to turn on "NFC transactions," then your phone doesn't support it.
At the moment, only a small number of mobile operators offer phones that support this feature. However, we're working hard to get additional mobile operators on board, and we expect the number of Windows Phones that support NFC transactions to grow.