What you did is perfectly fine, but I don't expect it to make any significant difference. Adding raisins will add some complexity, either way.I am trying a bariation of this. Rehydrated and fermented golden raisins - fermentation with skin contact. After fermentation finished, added to wine made from green grocery store wine grapes....hoping to add some complexity and a tad bit of sweetness. Will see how it goes.
You're not going to get a complex wine from eating grapes, as they are grown for quantity, not quality. But keep this in mind: If YOU are happy with the result, nothing else matters.
If the two batches ferment dry, the wine will be dry, e.g., lacking sweetness. It may be fruity tasting, but it won't have sweetness.
If you want some residual sugar, ferment dry, then dose the wine with potassium sorbate + potassium metabisulfite (K-meta), which acts as birth control for yeast. Then sweeten to taste.