Well, that's technically producer-side substitution, which can perfectly well be modded in (classic example - making fabric from cotton, or making it from wool). On the consumer side it doesn't work. Bundled goods are really a producer-side solution too; since the "bundle" is really one good from the consumer's perspective, you can't have different prices for different "goods" inside the bundle, only different production costs. A situation where, say, canned fruit is all the rage while nobody wants canned fish is impossible anyway, and as such, if canned fish can be produced cheaper per unit than canned fruit, it's the way to go, and nobody will ever grow tired of it. Direct consumer-side substitution is what you need if completely free price dynamics are to be viable.
I'm not dissing bundling (I'm going to do it in VRRP too, with liquor replaced by "beverage" that can be both produced in breweries and soft drink factories, for example), just saying it isn't sufficient, taken to any extreme, for making totally free price dynamics viable.