In my own thoughts only Ethereum can surpass the value of bitcoin, because lot's of projects now used the ethereum blockchain and this will make ethereum more popular than other altcoins.
Ethereum is much more than a cryptocurrency, unlike Bitcoin. Ethereum is actually a platform which is used by plenty of ICOs as well as other companies.The usage of smart contract mechanism is also boosting the value of Ethereum. This is one of the main reasons why the potential in Ethereum is pretty huge.