Hello Stephen,
Thank you so much for posting in Microsoft Community.
I appreciate you raising this concern to us.
The Surface Pro Signature Keyboard for Business is designed specifically for commercial use and comes with a warranty that is tailored to business customers. It is functionally the same as the regular Surface Pro Signature Keyboard, but it may have additional features such as a fingerprint reader for enhanced security. As for Bluetooth connectivity, all Surface Pro Signature Keyboards does not have Bluetooth capabilities.
See this link for more: Surface Pro Signature Keyboard for Business - Microsoft Store
Hope it helps!
Best regards,
Rolando S.