$350 is likely for ethereum. The price recovery has been so easy for bitcoin and other altcoins are also being influenced by that recovery of the king. And if the dominance of bitcoin decrease all over the market, expect that money will come in to altcoins.
I think we al are waiting for this (atlcoins grow) as Bitcoin only for big whales nowdays. And when are you expecting Bitcoin dominance decrease? In last bullrun altcoins were growing like crazy together with BTC....
Remember the first month of 2018. It was awesome for altcoins because just started to decrease overall by that time in terms of dominance and price. They may go as high as bitcoin shows whenever it comes but that's it.
If bitcoin dominance increases, as you can see right now the movement for most alts and to be more specific with Ethereum it wasn't what we are expecting. However the total impact that we can see right now, it's all good and working in progress.