All applications that are available on the iTunes App Store are only for iPhone and iPod touch. None of those apps (including our games) will run on either Mac or Windows computers.
Where did you purchase the Mac version of Virtual Families? If it was directly from us, you will be interested in
this answer in our Support FAQ.
I'm not sure how you purchased Plant Tycoon from the iTunes Store, since the only LDW games that are available there as of this moment are Fish Tycoon, VV2, and Virtual Families. There is also the mobile version of VV1 (developed by Vivendi/Big Fish Games), which is not the same as our Mac/Windows version of VV1.