Nicola, there are many possibilities here, but nothing to be too concerned about, I don’t think. One is that wine isn’t all that addictive for you; that it’s more of a take-it-or-leave-it kind of thing. I suggest you just make a mental note of what happened, and see how it goes next Wednesday, and the one after that… Maybe on one of those Wednesdays you’ll have the wine, so see what you like or don’t like about that to inform your choices in the future.
My main comment, though, is that you’re thinking in terms of “making a Plan” (with a capital P) about the wine. This isn’t using the technique of “Plans” as I describe in Week 4, the purpose of which is to eat less of a snack or meal than you would have done, as a way to take control of snacks or meals and eat smaller versions by making a Plan just before you start eating.
What you did in not buying the wine seems fine to me; it just isn’t a “Plan” in the way I use the term. I do suggest you make a point to remember what (if anything) you liked about not drinking wine (and not eating crisps) because that’s what will motivate you to continue – assuming you want to.