It makes no difference whether the actual page is located directly under the web root for your website. It can be placed several directories deeper on the server without any problems.
The important thing here is how many steps it will take for the search engine crawlers to reach this page. The easier it is to get to a certain page via links on your website, the more important this page will be considered from visitors and search engines. Naturally, pages that are linked on your home page will be given more weight by the search engines.
