Hey Rumbledesign,
as I mentioned, the “Portfolio” page template always displays projects from all available tags – since it is not a taxonomy page by design, it does not discriminate between the projects of different tags. The only way to display only certain tagged items on one page is to use the tag archive pages. Alternatively, one would need to tweak the “page_portfolio.php” template or create a new page template on the basis of that to display only some tags; this can be done by altering the wp_query (line 65) in the way described in the WordPress manual.
Sincerely,
Andrii / Satori Studio