That depends upon the seller of the theme. Contact them if their license is not clear about this. I ran across a couple of sellers of plugins (not sure about their themes) that have a special license specifically for multisite networks, while others say that if the sites are related in use (say one business’ main site and the same business’ blog site), you only need one license but if the sites are for different businesses, you need a license for each site. Whether the sites have their own domain names rather than just subdomain names can make a difference too.
