The midfielder, who was diagnosed with a pelvic shear last year, set up Billy Knott and scored himself before Brendan Moloney pulled one back for the visitors.
Knott opened the scoring in the eighth minute, meeting Bloomfield's low cross from the left to curl home left-footed from the penalty spot.
Wycombe's Anthony Stewart denied Marlon Harewood with a last-ditch tackle in the 20th minute shortly before Frank Fielding saved his close-range effort.
Knott then turned provider. flicking the ball neatly into the path of Bloomfield, who slotted home calmly from 10 yards.
Paris Cowan-Hall almost made it three in first-half injury time, skipping in from the right flank and forcing a low save from Fielding.
Moloney struck back superbly 11 minutes after the break, picking up the ball 25 yards out and slamming past Matt Ingram but the Robins failed to find an equaliser.