Both my NW and DL BPs all say SkyTeam elite (had to call DL to get WP# added before this showed up on my DL itin.).
EDIT: That is if your FF# is on your NW PNR then your SkyTeam elite status should be on your NW issued BPs. If it's not make sure they have both your FF# and your status on the PNR and have them reprint your BPs.
Well, as mentioned, my itinerary shows SkyTeam Elite (on their online reservation management tool). Hopefully my BPs will, too, and if not, I'll just show them my itinerary and they'll have to live with it.
Wanna hear something funny though? One time I called the NW call centre to sort something out about my ST Elite status. The agent and her supervisor were completely lost, and asked me to spell both "Alitalia" and "Millemiglia" to them, saying that "nobody here has ever heard of that airline before"...
Live & Learn!