There is variation in the design of Speaker docks. Some obtain analogue audio and some digital audio signals from the Apple devices. Also the choice of pins for collecting the audio signal may vary. Hence our Bluetooth devices require testing to determine compatibility with individual speaker docks. This is why we are specific about the make and model of speaker when describing and selling our Bluetooth adapters.
If your speaker dock is not listed, please inquire. We may have tested, or can specifically test, for compatibility for your make and model of speaker.
In most cases you should not be concerned with the versions of Bluetooth. As defined by the Bluetooth standard, all new versions of Bluetooth are backwards compatible with older versions of Bluetooth.