There is no such thing as "bottlenecking"
If, by that, you mean that upgrading a cpu or graphics card can
somehow lower your performance or FPS.
A better term might be limiting factor.
That is where adding more cpu or gpu becomes increasingly
less effective.
In your case, how well you do will depend on how cpu limited your games are.
If you play fast action games that are graphics limited, you will do well.
My suggestion is to buy your 4k monitor first and then see how you do.