According to this thread, the answer is no.

http://www.flyertalk.com/forum/marri...b-lounges.html

If you get a Ritz Credit card, it comes with 3 upgrade certs for the first year. Otherwise, I understand you can pay for lounge access. At a couple hotels of interest to me, the cost is $100 and more per day.

I hope that you report back on the RC Istanbul. I've just begun to look at Ritz properties, and have my first stay booked.