The Family Pack is meant to be used for Macs in the same household but that can be ignored in the same way that people install the Single User version on several Macs
About the Family Pack
The Family Pack Software License Agreement allows you to install and use one copy of the Apple software on up to a maximum of five (5) Apple-labelled computers at a time as long as those computers are located in the same household and used by persons who occupy that household. By “household” we mean a person or persons who share the same housing unit such as a home, apartment, mobile home, or condominium, including students who are primary residents of that household but reside at a separate on-campus location. This licence does not extend to business or commercial users.