i5-750 bottleneck a gtx 660ti ?

Depends on how CPU heavy the game is, in most games you will probably be okay. In some games, the i5 750 will be a bottleneck to an extent if you are running it at stock clocks. Some examples would include Far Cry 3 (I hit a very slight CPU bottleneck with my i5 760 and a Radeon HD 7870) and Hitman Absolution (that game gets really CPU heavy in crowded areas).

If you do run into a bottleneck with the games you play, you can try to overclock your CPU to alleviate the bottleneck. Lynnfield CPUs can get a decent overclock usually, provided you have a decent motherboard and a decent aftermarket CPU cooler.