So what I think you're describing is a feature of your theme's author archive template rather than something that WP Biographia can do.
WP Biographia can append or prepend the Biography Box to a post or to a page.
What it can't do is to add the Biography Box once to an archive page that can contain multiple posts, such as the author archive page. This is something that your theme's template controls, not a plugin.
It's relatively trivial to add the Biography Box to a theme which adheres to the stock WordPress theme structure, such as Twenty Ten. But your theme is a premium/paid theme and that's something I can't help with. Not because I won't but because it would cost me almost $90 to get a copy of the theme and because as you've paid for the theme, your theme provider should be the one giving you the support you've already paid for.
You'll need to ask them how to modify the theme's author archive template to include WP Biographia's
wpb_the_biography_box template tag before the posts. They can find documentation on this template tag here: http://wordpress.org/extend/plugins/wp-biographia/other_notes/