I\'ve been looking at iOS 7\'s new P2P networking framework, MultipeerConnectivity, and from the description, it seems to me that it uses a combination of some kind of Wi-Fi
No, the two are not compatible.
The MultipeerConnectivity documentation you linked to explicitly states (emphasis mine):
The Multipeer Connectivity framework provides support for discovering services provided by nearby iOS devices
Although you may be able to hack together a workaround akin to the short-lived iMessage app for Android, I wouldn't recommend it.