Bartomeu has made a personal decision to send a letter to RFEF president Luis Rubiales regarding VAR, according to RAC1.
In the final minute of the game, Barcelona are appealing for a penalty as Pique goes to ground in the six-yard box following Suarez's delivery, but the referee says play on.
Bartomeu doesn't understand why VAR wasn't used in the Piqué incident nor the overall usage of it. He'll remind him that Barça were one of VAR's defenders early on.