When the inevitable happens and Bitcoin's price plunges...how does the Alt market fair? Has it become strong enough independently to grow during a Bitcoin price correction?
it depends on a lot of things.
what you are calling a "crash" now may not even be a crash in the future. there simply can be a small correction and then another medium size accumulation phase before the rise continues like most of the times in bitcoin. there is no more FUD so this is actually a good assumption.
but also there may be some FUD and some panic during the 2 MB hard fork that can split the community once more like the pre August stuff. and that can be a crash. maybe down from $5000 to $3500 even.
in that case first altcoins will get dumped hard too. this is completely natural and it has happened every single time bitcoin crashes. but if bitcoin stays low after the crash we may see another series of big pumps in altcoins. ant the timing will also be perfect.