The other way that I've done it in the past is to upload a CSV of users to Moodle's "Upload Users" page without making any changes to the users (just export username, firstname, lastname, email from reportbuilder).

On the second screen, before running through the import, you can select the option "Select for bulk user actions". 

Once complete you can then use the bulk user actions interface to carry out various actions including adding users to cohorts/audiences.

Obviously its not as straightforward, but I tend to prefer this approach as it gives a bit more flexibility.