Yes in the short term, and no in the long term and this is why:
Bitcoin is the most established and well known cryptocurrency. That being said, there are better ones out there, and this is objectively speaking. In example, Monero does what Bitcoin does and it provides complete privacy and anonymity. The Bitcoin ledger is public and transparent. I personally prefer privacy and freedom over banks and government snooping. My money is my business.
So, to purchase some of the lesser mainstream coins such as Monero, one must first purchase Bitcoin in the vast majority of cases. This sort of reserve crypto status that Bitcoin enjoys is the second reason, the first reason was notoriety, for its continuing rally. Just in the last month, 130 billion has poured into the cryptocurrency market and much of this new money was absorbed by Bitcoin but a lot of it went into alt-coins as well. Note: alt-coin is an alternative and usually lesser known coin such as Monero, Ripple, Stellar Lumens, etc.
As other currencies gain popularity, start being used in the real world, and as a medium to getting alt-coins, we are going to see a decreasing Bitcoin dominance.
But, for the time being, this Bitcoin rally is great for the market as a whole. Good times ahead!