Remember that bottlenecks are a bit of a red herring, as there is no "one bottleneck" in a system. The bottleneck changes based on the application. So what's important here, is the actual application you are running that you are experiencing this.
If the CPU is hitting 100% it is by definition, "bottlenecking" - but remember what is a CPU bottleneck in one game, might be the GPU bottlenecking in another.
In one game the CPU might bottleneck heavily, where it is more CPU intensive.
In another, it might completely swap, where it is more GPU intensive.
So this can largely depend on your monitor refresh rate and resolution, what games you play, and what settings you play them on.
Overall however, I would say for the most part (generally) the 2700X and 2070 will be fine together.