To answer your question, yes, a GTX1050ti can be used with a 9900K as well as with any other processor you might care to use.
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.
What is your current cpu and gpu?
One or the other will be your limiting factor for YOUR games.
Try this simple test:
Run YOUR games, but lower your resolution and eye candy.
This makes the graphics card loaf a bit.
If your FPS increases, it indicates that your cpu is strong enough to drive a better graphics configuration.
If your FPS stays the same, you are likely more cpu limited.
As to a processor upgrade, there are several options, depending on your budget.
The newly announced amd 5000 series would be a strong upgrade, if... you can buy one.
Coupled with a ipc boost and a clock around 5.0 that would be the strongest upgrade.
Today, with your apparent budget of $300-$400 for a processor, I would look at the i5-10600K.
The top clock for the 10600K will be similar to the 9900k, 10700K, and 10900K.
That is what a game like CSGO needs.
The difference is in how many threads you get. 12 threads for a 10600K should be more than enough.
Few games can make effective use of more than 4-6 threads. Multiplayer excepted.