A bottleneck is a situation in which one component is weaker than the rest of the system, so all the stronger components do not perform optimal. In the common usage of the word "bottleneck" - it is the narrowest point obstructing the flow.
"your gpu is so strong that your CPU cant keep up"
It is exactly the opposite. Your CPU is the weak link - it is a CPU bottleneck. The CPU is the neck of the bottle, the narrowest part. The CPU does not let your graphics card reach its potential.