Whilst I refine my own smartphone binaural recording technique (very much wired as at now - if you are able use a cable, right?!) it seems at least two wireless bluetooth binaural products are in the works.
One is OpenEars by Binauric.
The other is the Hooke Audio Verse.
Whilst prototypes are in use in both these wireless cases, I've been using my wired OKM-II for quite some years now and always pleased with the results when the iPhone actually bothers to record the video with a stereo soundtrack.
That's the biggest issue turning me off my current wired solution: unpredictable with iPhone video recording - sometimes you end up with a mono video. I could record double-system reliably but it's just not cost effective and just adds a layer of complexity.
What turns me off the wireless solutions, assuming they make it to market, is yet more battery management/recharging in the field. Boring!
This does however show that binaural recording is getting a respectable foothold in the modern market, albeit nascent from the mainstream perspective right now.