We 've been through that before. CO don't follow what is accepted policy by every other ST member worldwide.
It appears that some local managers of other airlines have realised this and started reducing cross-alliance privileges on local cost-cutting initiatives. This is most definitely a local issue, as I had it happen at AGP and when I wrote a letter to AF (who were implementing a "FB only" policy at the local AENA lounge), they replied apologising to me and promising that the situation would be resolved. Had AF HQ been the people who instigated that policy, they would've told me to get stuffed. But they didn't, so feel free to draw your own conclusions from that.