Yes, BONESET is a Scrabble word!

Letter values in Scrabble US: B 3, O 1, N 1, E 1, S 1, E 1, T 1.

Is it a valid word?

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

European herb having small white, pink or purple flowers; naturalized as a weed in North America
perennial herb of southeastern United States having white-rayed flower heads; formerly used as in folk medicine

Also: common comfrey, symphytum officinale, eupatorium perfoliatum.