Bluetooth and Wi-Fi are the computer standards in wireless transmission.
But there are other means too.
The D2 sends a 24bit/96KHz PCM stereo digital stream over-the-air in a "closed-system" Wi-Fi configuration. The system's proprietary RF technology ensures data integrity with no impact on existing routers or networks. The volume control on the D2 Sender is transmitted over an entirely separate channel so there is no impact on the digital audio stream.
Price: US$ 599
Wirless transmitter and receiver
One day I stumbled upon this post: A guy connected two audio devices by sending the S/PDIF over a wireless video transmitter.