We normally use yeast to make wine, bacteria and mold can ruin a brew.
With a fruit wine molds are common, that is why we mix the fruit in daily. Some bacteria (lactobacillus) can be interesting in a ferment, but acetobacter will turn your lovely fruit wine into a demijohn of vinegar.
I actually have a wild ferment going at the moment on a mead that is on the sour side that probably have a component of a bacteria ferment along with wild yeasts.
Wild ferments are an interesting thing to try, there is no guarantee that what you end up with will be enjoyable or even drinkable.