You can set a style that contains bullet information, but you cannot use it to apply to a paragraph that doesn’t already have bullets. So, you save the style, then create some bulleted text, then apply the style to that and the bullets and text styling will be updated accordingly.
Yes, exactly. The limitation is partly down to the way bullets work in Apple’s text system. Suppose you want bullets that are numerical on the top level and then alphabetical on the next, for instance. There’s no way of applying that style on only the outermost bullet - as soon as you hit return and tab, you’ll end up with a regular bullet. But applying the style afterwards can update all the bullets as necessary. (It’s a system I would like to improve in the future, but it requires overriding some of Apple’s bullets system, which is somewhat messy and involved.)