Vidal, 31, spent three seasons at Bayern Munich before completing a €18m transfer to Barca this month.
However, during his time at the Bundesliga giants they were knocked out of the Champions League twice by Los Blancos.
Controversy surrounded both occasions with alleged favouritism of refereeing in favour of the Spanish side, which the Chile international eluded to.
"With VAR, Bayern would have had two more Champions League titles," the new Barça midfielder claimed, as quoted by AS.
The former Juventus man further went on to highlight his ambitions after the surprise switch that sees him replace Paulinho in Ernesto Valverde's squad.
"I have come to win everything, arriving at a new team, a new competition, and LaLiga excites me a lot."