The 39-year-old, who will combine his duties with those of goalkeeping coach for the club’s Centre of Excellence, was part of Glen Maddison’s coaching set-up in 2011-2012.
Bunce will now assume full control of reserve team affairs following Maddison’s switch to United Counties League side Sleaford Town.
The make-up of Bunce’s own support team will be announced in due course.
The Pilgrims’ second string will once again be competing in the Sills and Betteridge Lincolnshire League in 2012-2013.