Most fruit will contain some indigenous yeast but there are a couple or three issues for new wine makers:
1. The indigenous yeast may not produce a wine whose flavor you like - Yeast, after all, are not simply catalysts but they impart flavors, enhance flavors and mask flavors and wild yeasts are not the same as lab cultured yeasts where we know the characteristics of the yeast (see spec sheets).
2. Indigenous yeast may not have the tolerance for alcohol that lab cultured yeast has so you may find that your batch quits fermenting with very little of the sugars fermented out.
3. The number of viable yeast in the fruit may be tiny (relatively speaking) and so other spoilage organisms (mold, for example) may do their work before the yeast has a chance to ferment the sugars.
What I tend to do is take off a small sample of fruit and see what any indigenous population of yeast can do with it while treating the larger batch to cultured yeast. If I like the effect that the indigenous yeast bring I simply buy or obtain more of the fruit and use the sample as my "starter" for this second batch. Typically, I do this with raw honey (mead making)- sometimes it works and sometimes it doesn't.