I can't see any reason why you wouldn't be able to use an external bluetooth dongle to link up with your S9s, I suppose the only thing would be how the software worked on the iphone, I'm presuming here you're talking about something specifically for the iphone rather than the ipod?
Having tried a LOT of bluetooth headphones I can honestly say I hate them.. without exception. Give me a set of shure/ultimate ears/sennheisers anyday, even my trusty skullcandys (awaits flaming as audiophiles seem to hate them) over fidly pointless bluetooth sets anyday.
And surely getting caught up in a cable is only an issue if you're naked?
Tshirts/sweatshirts were made for threading cables through.