Well, it seems almost all the top 100 coins on the coinmarketcap experience both the bear and bull markets together. Whenever there is a dip in Bitcoin, Ethereum follows, hence, showing no potential of surpassing Bitcoin. Ethereum is doing well but i think it still deserves the second position for some time because the difference in their market volume is huge.
Now, Bitcoin has approximately $4.6 billion whereas Ethereum has $1.9 billion.