http://www.usairways.com/en-US/divid...d/default.html
Interestingly, the benefits page says "any flight" and not "any international flight" for lounge access.
"Lounge access for frequent flyers by tier status
Enjoy exclusive access to premium airport lounges around the world with oneworld Emerald or Sapphire frequent flyer tier status. Members of oneworld airline frequent flyer programs with the equivalent of oneworld Emerald or Sapphire tier status can use any lounge offered by any oneworld airline when departing on any flight marketed and operated by any oneworld member airline, regardless of cabin class being flown.
Emerald tier frequent flyers can use First Class, Business Class or frequent flyer lounges.
Sapphire tier frequent flyers are welcome in Business Class or frequent flyer lounges (does not include Qantas Domestic Business Lounges).
Emerald and Sapphire members may invite one guest to join them in the lounge. The guest must also be travelling on a flight operated and marketed by a oneworld carrier.
You must be prepared to show your boarding pass and frequent flyer membership card, with oneworld Emerald or Sapphire tier status, to access a lounge."