How long did you let the wine clear after adding the bentonite? You said you stabilized with Campden Tablets, did you sweeten too?
My first thought is that it needed a couple of more days to settle before racking and bottling, so there may have been additional particulate material that had not finished falling out of the wine. My other thought is that Campden Tablets do not kill wine and beer yeasts or inhibit their growth in typical dosages. Campden Tablets (either Sodium Metabisulfite or Potassium Metabisulfite) are designed more for anti-oxidant additions than killing Saccharomyces Cerevisiae, to inhibit yeast growth you would also need to add either Sodium Benzoate or Potassium Sorbate with the Campden.
If you really want to make sure the yeast is out of the wine, then you'll need to filter. Otherwise, a popular strategy is to stabilize with Campden and Sorbate or Benzoate and then bulk age, racking about every 30 days, until you no longer see fresh lees at the bottom of the fermenter when it is time for the next racking.