Once terms have been added to the Publication Topics vocabulary, they can be added to the Publication Topic Terms section on any publication node edit page.
Once a term has been added to a publication, it will be included in the Filter by Topic bar in the default Publications list page, and will be displayed:
In the Related Topics section of the individual publication page.
Publication terms can also be used as arguments within the Lists paragraph, which will allow you to create organized lists of publications on any page. See Lists for more information.