Los Angeles to the Bay Area in an hour
Van Nuys to San Francisco International is 320 miles, about an hour in a light jet and a few minutes less in anything larger. San José is 291 miles from Van Nuys and Oakland the same 320, so the Bay Area airport you choose changes the drive far more than the flight.
The flight is short enough for a day trip: a board meeting in SoMa, an investor meeting in Menlo Park, a tasting in the Napa Valley. As an illustration, a departure from Van Nuys at 8 lands at San José a little after 9, and the aircraft can wait on the ramp to fly you home in the evening; the actual times depend on the aircraft, the crew's duty limits and the airports on the day, and are confirmed with the quote.
The airline alternative is the shuttle from LAX, with the drive to the airport, security and a terminal at each end, or six hours on Interstate 5. A private flight leaves Van Nuys or Burbank when you arrive.