Morgan,
Connecting to San Francisco requires a bus ride. The trains server Emeryville on the other side of the bay from San Francisco. The Zephyr ends its run in Emeryville, so you have to get off the train there no matter what. Then you'd just hang around the station most likely, unless you actually want to cross the bay for a few hours, and catch the northbound Starlight when it comes through.
You will have to tell Amtrak when booking that you want to connect in EMY, instead of SAC. And if the Zephry runs late, then you need to be proactive and communicate with the conductor of the Zephyr regarding what to do if you won't make the connection in EMY.
You should also know that EMY is a new station with no history, while SAC is an old station with history. There is also more around the SAC station than there is around the EMY station and that must be considered as you'll need a meal no matter where you decide to switch.
Connecting to San Francisco requires a bus ride. The trains server Emeryville on the other side of the bay from San Francisco. The Zephyr ends its run in Emeryville, so you have to get off the train there no matter what. Then you'd just hang around the station most likely, unless you actually want to cross the bay for a few hours, and catch the northbound Starlight when it comes through.
You will have to tell Amtrak when booking that you want to connect in EMY, instead of SAC. And if the Zephry runs late, then you need to be proactive and communicate with the conductor of the Zephyr regarding what to do if you won't make the connection in EMY.
You should also know that EMY is a new station with no history, while SAC is an old station with history. There is also more around the SAC station than there is around the EMY station and that must be considered as you'll need a meal no matter where you decide to switch.