cnk,
US does not offer bassinets on any domestic flights. US flies 3 types of a/c on its transatlantic flights...the A330, the 767 and the 757. Unfortunately they only offer bassinet service on the A330 and the 767, not on the 757. Have you considered 3 seats in Y for your international flight? It would give you more room and some times works out to be cheaper than the 10% infant fare and taxes for business class if you fly with a lap baby.