I experienced the "champagne" like affect and it's been from a couple different reasons. Fruit has a tendency to add that sweet aroma and taste you like, but because of the water in the fruit it can look and feel a little more watery than a standard non-fruit beer. The sugar from the fruit can also dry the beer out leading to a wine or champagne like dryness. Honey will also have the same dry and added water effect, pair honey with fruit and your almost guaranteed (in my opinion) to have a light color, dry, watery mouth feel, and overall wine/champagne like beer.
The other factor you have going for that's a big impact on your beer is exactly what you included in your ingredients, the yeast. Without knowing exactly what the yeast was I'm just going to guess that the yeast dried your beer out.
I also just did a quick search on what the Pouch Booster was, and according the forums, if you add the booster it has a "drying" effect on your beer. It seems to be more sugar of some kind, perhaps something like corn sugar.
Add all this together and I'd believe you'd have a champagne like beer.