No one can tell on when it would happen but basing off on history. ETH almost reached nor surpassed Bitcoin dominance in the market and that was on June 19,2017 on where

ETH dominance do able to rise up 31% while BTC is on 37% which is really already considered as a close gap and the next one being nearest was on Jan 29,2018 which it do able

to hit 33% versus 20% in dominance which is also near as we can say but now on the current market condition where that gap is nowhere to be found.Bitcoin is dominating

the market after all the years had passed.So its really hard to tell on when ETH will overtake Bitcoin in any angle.It might able to get close or go near but it wasnt successful
on surpassing it.