Though this is off topic question still i would like to answer it. I regularly buy theme from both wrapbootstrap and themeforest.
I think you need to buy single application license if you buy from wrap bootstrap thats awesome thing about wrapbootstrap while themeforest suck if you charge user you have to pay 50x price of single license and get extended license for single product.
According to wrapbootstrap docs it states about every license.
Use of an item is bound by the license you purchase. A license grants you a non-exclusive and non-transferrable right to use and incorporate the item in your personal or commercial projects.
For more info : http://support.wrapbootstrap.com/knowledge_base/topics/usage-licenses