The plant, which currently produces the Gol and Voyage models, employs around 3,200 workers and is starting a new production cycle after the implementation of Volkswagen's "MQB" modular design strategy.
The first car to be produced under the platform will be the Polo Track model, which will be launched next year, the union said.
Volkswagen did not immediately reply to requests to comment on the matter. The terms of the agreement were not disclosed by the union.
Last week, workers at Volkswagen's main Brazil plant in Great Sao Paulo's Sao Bernardo do Campo, accepted a wage decrease and a cut in working hours starting in July due to the lack of auto parts and electronic components.
($1 = 5.1822 reais)
(Reporting by Alberto Alerigi Jr.; Writing by Peter Frontini; Editing by Chris Reese)