The site CLI command is missing the commands to interact with all caches.
There are 2 options to achieve this:

Option 1: the command depends on the context.

If the command site bring-online --site=NYC is invoked in the path

• /containers/default, it is a global operation and affects all caches
• /containers/default/caches/my-cache, the command is invoked in cache my-cache
• If --cache=my-other-cache is set, the path is ignored and the command is invoked in my-other-cache cache.

Option 2: duplicate all sub-commands. For example bring-online duplicate to bring-online-all and so on.