Virgin's website states that they use the LATAM lounge in the south terminal. They definitely give out lounge invitations to Upper Class passengers, but not sure if that extends to Virgin passengers in other cabins, with SkyTeam status.
From memory, I recall SkyTeam status passengers were expected to use the Delta lounge, which should close at 20:45 and not 19:30. Previously it used to be open a little later than 20:45 though.