Bitcoin and altcoins ties are very weak.
They are powerful right now, just because ALL cryptocurrencies are mostly used for SPECULATION.
This means when people see Bitcoin is raising, they trust more that all altcoins will be useful as well... which is not necessarily true... and probably just not true at all.

Once Bitcoin will become mainstream for USE (buying goods), then it will REALLY take off and blow up to 10000$ in few months, then to 100000$ in another year.

But at that point, altcoins will stop at the bar for a very simple reason: Bitcoin will take off because it will be possible to use it to actually BUY STUFF.
That's because it has been implemented as a method of payment on thousands and thousands of shops and services, thing that is NOT happening with altcoins.

It MAY happen in the future, though, especially for Litecoin, imho.
But in first instance, altcoins could take a severe hit when Bitcoin will boost to the Moon, exactly because people will understand that its value is in its spreading in the mainstream as a way of buying goods, and altcoins could be seen as a failure as they will remain in there only still as speculative currency.