This is the reply that I received from Typography.com’s representative, Ms. Melissa Marovich:
Thank you for getting back to me with respect to this. The Multipurpose font family package and the ScreenSmart font family packages are two separate font families. In order to receive both of them, you need to purchase both the Gotham Bundle Multipurpose and the Gotham Bundle ScreenSmart font family packages.
From what I understand, we need ScreenSmart for the web, but that doesn’t look too good on print or high res devices. Unfortunately, ScreenSmart is not included with Multipurpose font as Melissa explains.