New in iOS 6.x, even if you turn Bluetooth on, your phone will turn it off again if there are no devices paired to your iPhone. This makes TokenLock (or any other bluetooth monitoring apps) stop working. This video shows you how to use TokenLock with an iPhone and make it work.
The key here is to make sure your phone does not turn off Bluetooth automatically when you exit the settings screen. Make sure your phone is "paired" with something, so that it remains on. It can be paired to anything - your Mac, a headset, your Car… or the rental car autio system you used last summer…. or just about anything else.