China Airlines agents in LHR (on a skymiles ticket for relevance) did not allow me to through check my bag to a Sep tix Philippine Airlines flight from Taipei to Manila. The frontline agent was willing to and was able to add the flight to the reservation but she had to ask her colleague who then said ask supervisors who said NO. I just took it as my 2nd carryon to avoid re checking in and doing immi. I imagine the agents in BNE would be similar but it could make a difference that you are on SkyTeam