Germany and Japan were of course Linked Up in terms of cooperation. The Germans even sent a Q Ship to show the IJN how it was done (US sub sunk it before it got there). I don't know if there were specific plans but it was a logical move for them.
I guess we could start a looong thead on the subject, but I recall reading an analysis by an "expert" saying that the campaign in the Med was a waste of time for the Allies. Given the potential for German capture of the oil fields in the ME and the possibility of a German-Italian-Japanese physical link-up I think the man is an idiot.