NW doesn't market that route - they don't have published fares for it, IIRC. You will still get your elite benefits on NW metal, regardless of who ticketed it. FWIW, I've alwas found US to be more cost effective on that route, but it's *A, not SkyTeam...
And, I know this is FT, but flying via DTW to PIT ex-BWI...it is just much faster to drive, IMHO...