Experience with Skyteam lounge access seems to vary by lounge and airline. There is a lack of consistency and a lot less flexibility compared to *A (UA, US and AC, for example, always let me use their lounges on domestic flights with a BD Gold card).

In November, I was refused access by CO in EWR to one lounge only to be admitted to another in the same airport on the same day (I had a F ticket on a domestic flight, connecting from an international flight the day before). NW and AZ are generally pretty flexible. AF is the worst.

Today, I arrived in GVA on a AZ flight in C class. I had a 6 hour layover for my next flight, which was a LX codeshare on AF metal. AF lounge refused me access, even though I was flying them, am FB Platinum and had flown on an international Skyteam flight the same day. It's called being generous by nature (FB slogan).