The 26-year-old, who denied the Football Association charge against him, has also been fined £40,000.
The incident occurred in the 83rd minute of the Cherries’ 1-0 defeat at Hillsborough on 3 November last year.
A Bournemouth statement said the club were “surprised and disappointed” at the decision by an independent panel.
Windass said he felt Lerma bite him on the shoulder while marking the Colombia international at a free-kick during their Championship encounter.
The Owls player reported the incident to the referee and said the contact left a “red mark” on his skin which “looked like a rash”.
The independent regulatory commission heard that video recordings were “not conclusive”, while Lerma said the fact he wears a mouthguard while playing would make it “impossible” for him to bite an opponent.
“Since the start of this unnecessarily long process, Jefferson has strenuously denied the charge and has been fully supported by the club in doing so,” the Bournemouth statement added.
“The club believes there was a lack of clear and compelling evidence in finding the charge against Jefferson proven, and the player is currently considering his options regarding an appeal.”