The mentioned South Bay locations are xAI's Palo Alto office, and an office in Santana Row. Both locations likely have connections to Caltrain.

I don't know where xAI's Palo Alto office is, but transit in the corporate Palo Alto office are generally good. If xAI is in the Stanford Research Park, you'll be taking a shuttle that runs only during commute times, and takes 15-30 minutes, depending on where exactly you get off.

Santana Row is more confusing. You'll travel either to Santa Clara or San Jose and take a bus. From Santa Clara, the bus is ~15 minutes. From San Jose, the bus is faster, but you've got a half- or one-mile walk.