Found this in the "Help Center" link below.
You can spend your Loyalty Points when purchasing models participating in the Loyalty Program (they are marked with a piggy bank icon and show a discount you will get with your Loyalty Points). Points can be used if the total value of your cart is equal to or greater than $15. They will be applied automatically and will cover up to 30% of the price.
So if the artists of the models you want, don't participate in the Loyalty Points Program, you don't benefit.