There are no benefits for being Tutor.
Well if you write as tutor on the Help channel, then your text is orange. I think we can call it as a small benefit because everyone knows that you are a tutor.
We can find on TibiaFandom that Tutors assisting Customer Support. They are finding and reporting bugs in an everyday capacity and in private Test Servers. They have access to the internal Tutor Board and also to a Tutor Fun Board and the Tutor Channel where they can discuss in-game with other Tutors or higher positions.
TibiaFandom - link