He doesn't have any power or control over the Bitcoin network, instead his control is on people who can be easily manipulated by FUD, if the Bitcoin network didn't have users who don't do their research and are thrown into confusion just by a single tweet, then even his manipulations wouldn't be possible.

Elon's tweets though can pump coins that are originally pump and dump coins, but his influence can't control such shitcoins and keep them up, cause with time they plunge/dump, in conclusion, if less users heed to whatever it is Elon has to say, the lesser his power/influence can be.