So I've been doing a bit more reading on the subject.
My Golf is a May 15 build, which is the first month of the MIB1 with the V3 "0031" SD cards, according to one of the other forums. I believe this had the updated Voice Commands. I know my Golf started with the 0031 version of ROW 2015 maps, which I've since successfully updated to ROW 2016.
Is it possible that it was at this time they changed from an SD card to a Voice Activation code for Voice Command. I think that the part number 5G0.054.802 is the same regardless of whether you have an SD card or activation code.
Am I over-reacting or should I just see whether the Activation Code will work on my MY15 MIB1?