Designed to add wireless capability to pretty much any MIDI instrument/controller, these are the BT01, which connects via a USB port, and the MD-BT01, which plugs into standard MIDI ports.
Once hooked up, these enable you to send and receive MIDI data over Bluetooth - the adapters are compatible with iOS 9.2 or later and Mac OS X Yosemite. Just select them as MIDI devices in your applications and you should be good to go.
See how they work in the video above, and find out more on the Yamaha website. No word yet on prices or releases dates.