When Christopher's friend "Murmur," standing outside the AA meeting, asks the guy from Yonkers if he's "lost," it recalls the title of the play and movie Lost in Yonkers.
Also, in the scene where Finn confirms Vito's sexual preference, the table and the seating of the crew around the table suggests The Last Supper in placement, as well as mood, as "betrayal" is an oft-repeated suggestion by Christopher, Paulie among others.