American Express Membership Rewards - Does AMEX Plat. allow access to more than CO clubs?

I've never had a problem getting into the Pres.Clubs, but will be flying to Rome next week--I know Pres. Club members are able to use all Alitalia lounges, and i'm curious if Plat. holders can use them as well.

Also, does the entry apply to Northwest clubs? do I have to have a NW ticket, or will a CO ticket be fine?

Thanks in advance...

I just did a search, and am pretty clear on what clubs to access with the card (or I could read the membership guide, but it's long since buried in my filing cabinet)

Sorry for the anxious/early post.

By the rules, you are only allowed entrance to the club of the airline you are flying. Partner clubs are excluded. However, I've found the NW clubs to be flexible. It's worth trying to get in.