Rich....while the octane rating is higher for ethanol the bad news is you get less power with all else the same. Octane is not an indication of "power" available form the fuel. In simple terms, octane ratings give you an indication as to the tendency of a fuel to pre-ignite under load which causes "ping" or "knock". How much power is lost due to the 10% ethanol blend I think would be small and the only way to find out exactly would be to do dyno runs. I do not know of any test performed where this was specifically done to evaluate the changes in power output but I bet the car manufacturers do know.
Engines designed to run on high percentages of ethanol CAN regain SOME of the lost efficiencies of using ethanol vs gasoline by having higher compression ratios, even greater than 11.0:1, or by using more aggressive engine timing. The result would be a higher HP output at the flywheel due to the compression/timing increases but still using more gallons of fuel (than gasoline) to do it.