Dwarven wine is made from a mushroom. Mushrooms do not photosynthesize, so they do not "make" sugars. However they do produce enzymes that can break down complex carbohydrates into simple sugars. Some species sequester these simple saccharides (sweet tasting compounds) inside their flesh. For instance, one species of truffle from Hungary
is said to taste sweet like honey. I do not think that there is a really good direct analog to plump helmets in the real world.
Being made from a mushroom, I expect an above average protein content, and a dark brown color, rather than purple, after fermentation. I would expect it to have a kind of "meaty" taste (strong
"Umami" flavor.)
Dwarven rum, made from sweetpods, is likely to taste a fair bit like normal rum, but the fact that it is not a distilled alcohol means it would be more like dark rum, with lots of plant flavinols present. I would expect it to be similar to the "Beer" created by many ethnic populations, created from the sugars found in the seed pods of various species of legume trees. I expect that the part that is brewed is the pod itself, which would explain why the seeds are not used up in the reaction. Many species of legume produce a sticky syrup or jelly like substance around the seeds inside the pod, such as that of Tamarinds, and Honey Locusts.
Banana beer is probably quite possible. Bananas contain a LOT of starch. The yeast that produces beer would break down that starch, and turn it first into simple sugars, and then into alcohol. Again, the flavinols of the plant matter would be present. I would expect a light amber color, with a strong banana flavor.
Whip vine is also its own thing. Without knowing more, I cant really guess too much about flavor. Personally, I would expect a clear liquor, and my imagination suggests something slightly cucumber flavored, or perhaps asian melon flavored.
Dwarven beer is likely to taste like any other beer. Especially if the cave wheat has a low protein content.