No, speaking in tongues isn't necessary for salvation. It's just one of a number of spiritual gifts that God gives to people. And if it was necessary for salvation there wouldn't be anybody in a Charismatic church who's saved because they all babble and fake it.

(1 Corinthians 12:8-11 NIV) To one there is given through the Spirit the message of wisdom, to another the message of knowledge by means of the same Spirit, {9} to another faith by the same Spirit, to another gifts of healing by that one Spirit, {10} to another miraculous powers, to another prophecy, to another distinguishing between spirits, to another speaking in different kinds of tongues, and to still another the interpretation of tongues. {11} All these are the work of one and the same Spirit, and he gives them to each one, just as he determines.