Does a dyno tune going to help improve the throttle response on my 2012 Grand Sport?

It should, depends on how competent your Tuner is. I have not ever tuned a C6, however I have had my 2011 Z07 modified and tuned a few times. There are many different parameters available to the Tuner that will make your car respond better. Make sure you work with the Tuner to advise on exactly what your expectations are for the tune.

Thanks.