Also, just to clarify, Wally's flight from Central City arrived in San Francisco first, and then since Gotham and Metropolis are both about equal distance to SF, I figured the planes from those two cities would arrive around the same time and that the four mentioned in the post (Dick, Rachel, Conner, and Jon) would share an Uber to the Tower. 

I will explain it more in my post next weekend, but the top floors of Wayne Tower West will serve as their "Titans Tower" for now. The top of the building is equipped with Martian cloaking tech so that it just appears like office space to outsiders, but in reality it will be a lavish multifloor penthouse with a pool and hot tubs and rooftop garden and plenty of space for them to eat, sleep, train, study, have superhero meetings etc.