The PortalWX permissions must be given to each company that is supposed to use the PortalWX; without permissions given to the company, no user created under the specific company will be able to register to the PortalWX and be the administrator.
Hierarchy in the permissions
Permissions given to the company can be assigned to the administrator created under it, but note that administrator can not receive permissions that were not granted to the company itself. Same goes for the new emloyes the administrator will be creating, administrator can only create another administrator of the PortalWX with the permissions that he was already granted.
For example, if the company has people, content, and guestbook permissions granted, then the first administrator can be created with managing people permission and content permission, but the second administrator created by the first one can only be assigned people or content permissions.