Simply put in the subject line. It seems that newsletters are now membership agnostic.
Yes, if you’re on Ghost <4.5.0 then you can select just paid members to send to:
And on >=4.5.0 the same feature is there but the interface is a little different:
And does the latter feature utilize tags of the members?
It utilises Stripe subscription status in the case of “Paid members”. You can choose a particular label to send to in the newer version too.