By default, Symfony 2 is delivered with a demo bundle which is just accessible from the development environment.
The production environment doesn’t contain any route, so it’s normal you get a 404 error page.
EDIT :
Are you sure your bundle is enable in the AppKernel.php ?
If yes, clear the cache with the following command : ./app/console cache:clear
Check if the route is enable with the following command : ./app/console router:debug