Jerry is making instructional videos and wants the audio to come through his bluetooth headset while recording it so he can do wirelessly. Leo says that the Bluetooth earpiece profile is only phone quality and that's not what he'll want to record quality audio. Leo advises recording to the iPhone via a lapel mic that's plugged into it. Or, he could try a Wireless system like Audio Technica. It would work great as long as he doesn't get a lot of RF interference.
Rode has the smartLAV, which plugs into the iPhone and is a professional grade microphone. In fact, any microphone plugged into the headphone jack will work.