Does anyone have a bike in which any bearing surface at all is aluminum? I guess Al chainrings would qualify, but who puts lithium grease on chains?

Headsets in an Al frame should be hardened steel. Al hubs have steel bearing cups. And most exposed Al on bikes is either painted or anodized.

I guess if you were using grease as an antiseize you might avoid lithium on Al frames. Could use PTFE-based stuff, or moly-disulfide grease, or lead-based antisieze, or this special stuff that Boeing uses especially for Aluminum:

http://www.armitelabs.com/products/B...nti-Seize.html