I have actually raised this very issue in this SkyTeam forum before... as a ST elite plus, I am allowed to use the FC check-in lines at the airport, board early, even get preferred seat assignments. But when it comes to the phone reservations lines, there are no benefits... we becomes "standees on the bus".
It would be a tremendous marketing advantage for any of the ST carriers to establish and publicize elite telephone numbers for ST elites. As soon as one did it, the rest would follow, assuming they could not coordinate this in the first place.
Heck, DL cannot even get its act together with its own platinums when it comes to international res lines.