Yes, TENURES is a Scrabble word!

Letter values in Scrabble US: T 1, E 1, N 1, U 1, R 1, E 1, S 1.

Is it a valid word?

TENURES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the term during which some position is held
the right to hold property; part of an ancient hierarchical system of holding lands

Also: term of office, land tenure.