Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: IB+ Gold, TK E+, Hyatt Globalist, Marriott LTP, IHG Diamond
Posts: 14,178
The international baggage allowance should apply to the connecting flight. Ultimately it will be tagged in IST even though you collect it at ORD and drop it off immediately after passing through customs.
Lounge is very unlikely - would AS even have one at ORD?
But you should earn TK miles on a TK flight code.