And this recently happened to when Bitcoin dumped. Call it a divergence of sorts. I think that showed me that Ethereum isn't going to dump heavily against Bitcoin anymore and has matured. Time will tell, but as each day passes I think the flippening is more and more possible.
Dependence on Bitcoin will still occur on every Altcoin including Ethereum, you can see the reality in any market when Bitcoin starts to Crash and when Bitcoin starts to be pumped back at different times.