Agree with geofelt. Bottleneck calculators dont really mean anything because having a bottleneck depends on the application you are using. With your rig for example, the 7100 will hold you back in some CPU heavy games because it is only a dual core chip. But in other games that rely more on single threaded processes, it wont hold you back at all.
I think your system is reasonably balanced, but if you are not happy with your performance (which will struggle in some games), then you can upgrade and you will get a boost in some games. A used 6700/7700 would be a decent buy as they are very good gaming chips and wont hold you back in the least.