Thank you for the info

i guess the AA-rules will apply:
http://www.flyertalk.com/forum/Forum71/HTML/004840.html
&
http://www.flyertalk.com/forum/Forum71/HTML/005279.html

On the day of an international departure on any one world airline, you get access to the AAdmiral's club if you
a) Are an AAdmiral's club member
b) Are PLT (One World Saphire) or EXP (One World Emerald)
c) Are traveling on Biz or FC on the int'l portion of the day's itinerary

You get access to the Flagship Lounge (or other One World FC lounge) on day of int'l departure if

a) You are traveling in FC on the int'l portion of the day's itinerary
b) You are EXP (or other One World Emerald)

When flying on American Airlines, how you got a business class boarding pass has NO BEARING AT ALL on lounge access or anything else. Paid full J, used miles to upgrade, or operational upgrade -- all get you the same boarding pass, and the same lounge access rights. All that matters is that you're flying in Biz class.