No. An author has publishing privileges only in those directories to which he has explicitly been assigned. Granting an author publishing privileges in one directory does not automatically give him access to other subwebs contained in that directory.

When you activate FrontPage, you'll assign publishing privileges to one author. This default author will be given publishing privileges only in your root web (your top-level directory). After activation is complete, you can activate subdirectories, or subwebs, then grant any of your authors publishing access to these subwebs.