I disagree. I think the KLM rules would apply since it's KLM-operated.

http://www.continental.com/onepass/e.../northwest.asp -- this applies to " All Northwest- and Northwest Airlink (Pinnacle Air and Mesaba Airlines)-operated flights" so this this is not applicable.

Whereas,

http://www.continental.com/onepass/earn/airline/klm.asp -- this appiles to "All KLM-, KLMcityhopper-, KLMuk- and KLMexcel-operated flights systemwide"

In fact, I don't think they know how it's ticketed -- NW, KL, or even CO -- when it posts. Generally codeshares post with the operating filght's code and number, regardless of how it was bought.

To be safe, though, if you can buy this as a KLM-coded itin (you may be able to do this with a NW phone agent), I would do that.