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 in the crypto network.
Other than Satoshi none have control over the bitcoin network, but lot many people have control over the cryptocurrency market. This is all because of the massive holdings of cryptocurrency. Elon is very much active on the cryptocurrency market in the recent days after finding the massive fluctuation. Now he tends to make use of the market for wealth generation making common people suffer.
Each and every tweet of him is taken into discussion. As he have got the ability to fluctuate the market there arises a big follower network that take buying and selling strategies based on his activity. In recent days it is the only possible way to profit. So, he have got good influence on the market.