Yes--you do extract some sugars, but I think your figures are a little high.
Crystal malts (the most typical steeping grains) run in the 33-35 points per pound per gallon range. And I usually figure about 40% efficiency of extracting sugars in a grain steep. So that would be more like 13 or 14 gravity points per pound per gallon.
So with typical grain amounts in an extract + grains recipe, you're probably only adding a couple gravity points with the grains (and that is largely unfermentable sugars).
Bottle conditioning: Robust Porter
Drinking: Saison Dupont clone, tripel
Coming soon: Columbus APA, Rich Red ale