I haven't explored 10.x yet, but this works in 9.3 & 9.4, you can try blocking Bluetooth network adapter to prevent file transfers via Bluetooth. This would still allow devices such as Bluetooth mouse, keyboard, headphones to pair and work fine.
Make sure to select both Bluetooth AND network adapter in the definition, otherwise DLPe will block network adapter and that won't be a good thing.
Device Control > Removable Storage Device Rules > Click [...] next to the blank txt box in the 'Removable Storage' row > select New Item when the Removable Storage catalog pops-up > Select Bus Type > Bluetooth ..
If you want more specificity as to what triggers the rule, build from there.