What is starbucks soy-milk policy?!

I have a registered starbucks card and I'm at green level. Along with a few other things, this level of membership includes the benefit of free soy milk in addition to my purchased drink. It says "Purchase any beverage on the menu with your registered Starbucks Card at a participating store and you can get select syrup and milk options on the house."

It expands and tells the specific syrups and milk options that you can get on the house (soy milk being one of them). The reason I ask this question is because I get a venti-size drink filled 1/4 of the way up with green tea and the rest of the cup filled with soy.

I'm wondering if I get that soy free even if it does fill the cup up majority of the way. Is tea considered the main part and the soy the addition or what? I would just imagine tea is normally considered the "main" drink no matter what the measurements are but I'm not sure.