Personally, I am a bit bearish in the short term so I think bitcoin dominance will remain high, but bitcoin's value itself won't go up, but just go down less compared to the market as a whole.
In the long term during the next bull run I'm sure bitcoin dominance will go down and as more coins enter the ecosystem. Not only will the value be disbursed more, I'm sure smaller marketcap coins will outperform bitcoin in general during the next bull run.