I wanted to follow up with this question in case any one stumbles onto it and is looking for the same thing
😄 You can look at the productType attribute to determine if the in-app product is a subscription. Monthly subscription has productType = "MonthlySub", Yearly subscriptions has productType = "YearlySub"
So you can do something like this ...
if item.productType = "MonthlySub" OR item.productType = "YearlySub"
print "CONGRATS, YOU ARE SUBSCRIBED"
endif