Here is the partner award chart between the Continental U.S. and the Indian sub-continent:


As long as you are not stopping over in London, this is the redemption chart which should apply, and there are no high taxes for merely connecting in London. (There are high carrier surcharges on long-haul BA flights.)

As long as you are using one or more partners in each direction, the roundtrip in Business should only cost 140K AAdvantage miles. (Loyalty Points are not redeemable for travel; they are only used to determine elite status.)

If you are only flying BA in one direction, and flying only AA in the other, that could explain the 180K miles for the roundtrip, as travel on only AA metal is dynamically priced.