Using white wine in the cooking
There are several things that come together to produce the overall flavor profile of the dish, not all of them having anything to do with the wine.  Traditional factors such as good spicing, blooming the spices, browning ingredients and so forth continue to have a huge affect.

Deglazing with some wine adds the following:


Acidity.  Wine is an acid food product, and this brightness can enhance the overall flavor of the dish.
Sweetness.  Wine can also be sweet, which acts as a flavor enhancer.
Fruitiness.  The fruity qualities of the wine may compliment the other flavors of the dish.
Alcohol.  The alcohol in the wine will not completely evaporate.  Some will remain, helping to dissolve and make volatile some flavor components which are ot soluble in either water or fats (this is especially true in tomato based dishes).  This can give foods cooked with alcohol an extra depth of flavor.


The first and last of these affects probably have the most profound affect on your dish.



Adding the wine in dribs and drabs probably doesn't help, but in the end you need to use enough wine to have a good effect on your dish.  Even though it will be reduced, it is still an ingredient, and you need to have enough to matter.

I do suggest adding it all at once, and letting it boil away; this should work quite well.

The quality of wine you use also matters.  You want a wine that tastes decent, even as a beverage.  My personal preference for cooking is a Chardonnay, but I don't think that preference is universal.