Bottlenecks don't work how you think they do. Every CPU bottlenecks every GPU, depending on the game and graphical settings.
A more useful question to ask is, "Can my CPU run the games I want to play smoothly?"
The A10 5700 is a low-end CPU, but it's adequate for at least 30-40fps in the vast majority of games. A 750Ti will let you get low to medium settings at that framerate.