The 27-year-old, who has most recently been on the books of Shaw Lane AFC and scored their goal against Mansfield Town in the First Round of the Emirates FA Cup in November, has linked up with his former manager Craig Elliott once again.
Bennett, who began his career at Lincoln City and enjoyed two brief spells in Sweden with Friska Viljor, has also played under Elliott at Glasshoughton Welfare and Ossett Town.
The Barnsley-born player has also appeared for Frickley Athletic and Buxton.
He is eligible to make his United debut, alongside fellow newcomer Ben Middleton, when the Pilgrims travel to Alfreton Town tomorrow.