Getting compile errors for NRF_SDK15=1

I just tried another build using BOARD=NRF52840DK and that works fine here - so as @fanoush says I'd definitely look at doing provision (you may have to delete all extra files in targetlibs/nrf5x_15 beforehand to get it to work them out again).

I can't find BLEP_BONDING_STATUS in any *.h file!

It's there:

./libs/bluetooth/bluetooth.h:  BLEP_BONDING_STATUS,              //< Bonding negotiation status (data is one of BLEBondingStatus)

So I think likely when you did git pull maybe there was some merge error? I'm not sure what changes you have made yourself but I'd consider checking out fresh from the Espruino repo and then trying to re-apply your changes on top of what's there now