Maybe /maybe not. If you pitched a pure strain it may have taken a majority share of the ferment, But I would lean towards 50/50% chance an unwanted wild yeast or mould has taken the majority of ferment here. You can rack a sample from the bottom of the vessel and see if it has clean, bright flavors/aromas then I would work with it further if it is any way offish you haven't put much time into it, just dump them and move on. Wild yeast wont kill you if you ingest their by product but if mould have the majority stake here you can create alot of mycotoxins in the wine.
Taste and smell will tell you many things.
You may have fermented with a natural strain of Saccharomyces cerevisiae, but usually the other natural wild yeast such as Kloeckera, Candida or Brettanomyces get a foothold first. Or moulds present on the grape skins/ juice can grow at faster rates than sacc yeast and cause obvious issues.
If it was lactobacillus, Acetobacter or Pediococcus bacteria introduced by the must or lack of sanitation then it will actually cause the must to start maloactic ferment early, turn to vinegar or cause ropiness.
Here are two small sources of info I found quick that will explain this stuff in more detail:
a. Yeast in winemaking grabbed from wiki:
The most common yeast associated with winemaking is Saccharomyces cerevisiae which has been favored due to its predictable and vigorous fermentation capabilities, tolerance of relatively high levels of alcohol and sulfur dioxide as well as its ability to thrive in normal wine pH between 2.8 and 4. Despite its widespread use which often includes deliberate inoculation from cultured stock, S.cerevisiae is rarely the only yeast species involved in a fermentation. Grapes brought in from harvest are usually teeming with a variety of "wild yeast" from the Kloeckera and Candida genera. These yeasts often begin the fermentation process almost as soon as the grapes are picked when the weight of the clusters in the harvest bins begin to crush the grapes, releasing the sugar-rich must. While additions of sulfur dioxide (often added at the crusher) may limit some of the wild yeast activities, these yeasts will usually die out once the alcohol level reaches about 5% due to the toxicity of alcohol on the yeast cells physiology while the more alcohol tolerant Saccharomyces species take over. In addition to S. cerevisiae, Saccharomyces bayanus is a species of yeast that can tolerate alcohol levels of 17–20% and is often used in fortified wine production such as ports and varieties such as Zinfandel and Syrah harvested at high Brix sugar levels. Another common yeast involved in wine production is Brettanomyces whose presence in a wine may be viewed by different winemakers as either a wine fault or in limited quantities as an added note of complexity.
Mould and yeast flora in fresh grapes:
Fresh fruits are prone to fungal contamination in the field, during harvest, transport, marketing, and with the consumer. It is important to identify fungal contaminants in fresh fruits because some moulds can grow and produce mycotoxins on these commodities while certain yeasts and moulds can cause infections or allergies. In this study, 251 fresh fruit samples including several varieties of grapes, strawberries, blueberries, raspberries, blackberries, and various citrus fruits were surface-disinfected, incubated at room temperature for up to 14 days without supplemental media, and subsequently examined for mould and yeast growth. The level of contamination (percent of contaminated items/sample) varied depending on the type of fruit. All raspberry and blackberry samples were contaminated at levels ranging from 33% to 100%, whereas 95% of the blueberry samples supported mould growth at levels between 10% and 100% of the tested berries, and 97% of strawberry samples showed fungal growth on 33–100% of tested berries. The most common moulds isolated from these commodities were Botrytis cinerea, Rhizopus (in strawberries), Alternaria, Penicillium, Cladosporium and Fusarium followed by yeasts, Trichoderma and Aureobasidium. Thirty-five percent of the grape samples tested were contaminated and supported fungal growth; the levels of contamination ranged from 9% to 80%. The most common fungi spoiling grapes were Alternaria, B. cinerea and Cladosporium.