Any of the vanilla stabilizers I've ever seen only says "fragrance" in the ingredients. Some of the suppliers have had it formulated specifically for them by chemists, so not every stabilizer will be the same.
Also, vanilla stabilizers may not work for every fo with vanillin in it. Some suppliers say that on their sites and some don't. Most suppliers have too many fo's to be able to test them all with it.
When you're using it in your soap, you don't change the ratio of it for the percentage of vanillin in the fo. You still use it according to the manufacturers directions, usually 1:1 ratio. But not always, some have different usage amounts, so make sure you're going by what they say.
The percentage of vanillin is listed on there to let you decide if you want to use stabilizer or not. A fo with a small percentage of vanillin will most likely just turn your soap a light tan or a dark cream color.
I personally don't use it very often anymore. Even with it, the soaps will still most likely turn brown if there's vanillin in the fo. Except now instead of it happening sooner, it happens later when the customer's had it for a while. Could you imagine being that customer who's got this pretty soap in their bathroom and then they come in one day and it's brown?
Plus, so many other fragrances can change soap colors also. Some will turn it a light yellow, some a light blue, etc. The vanilla stabilizer doesn't work for those fo's.
I've just learned to work with the color changes. This is another reason why it's good to have tested all the ingredients in soap extensively before selling.