The easiest way to achieve this would be to create a Last.fm account, install
the Last.fm audioscrobber plugin for your Windows foobar and configure it to
scrobble to that Last.fm account, and then set the Linux pidgin musictracker
plugin to source track information from that Last.fm account.
I suspect Wine might provide some means to interact with native IPC methods,
although I don't know enough about it to be sure, but using that would
probably involve writing some custom code to get the data from one place to
the other.