More fun with google -- S.666 is a senate bill aimed at giving the FDA more power to regulate tobacco products. One interesting thing about it was that the bill was introduced by Senator DeWine -- possibly a connection to the grapes clue? And the Pisco sours mentioned here and there in different episodes could also point to wine, as Pisco is a brandy made from grapes, which also make wine.
Of course I have no idea what to do with that information.
I've been googling Chilean wine and Pisco looking for anything that might shed light on the LIAr part of the clue, but not finding anything. It's possible, though, that the "grapes" and "s666" clues are meant to point out more than one player who might be linked to wine (who's been shown drinking it?), and the LIAr is meant to narrow that group down to just one, so the two halves of the clue don't necessarily have to be related.
Anyway, maybe a lot to hang on an obscure Senate bill! I'd be a little more confident of my interpretation if the clue had been written as "S.666-LIAr" rather than "s666-LIAr", but what can you do?