It wasn't a Latin name but the root of it is the Latin bene meaning 'well, correctly, good'. This element was in the name Benedictus 'blessed' which in English is Benedict, Bennett being an English medieval form. In Portuguese it's Bento, in Spanish and Italian, Benito. The feminine forms are Benedicta (Latin), Benta/Beneta (Portuguese) and Benita/Benitta (Spanish/Italian). All are rare now.
Bennetta seems a spelling variation of Benita and would mean 'blessed' :o)
Devon