For status match with an airline not in SkyTeam, see the Status Match Master Thread. Note that it is generally a once in a lifetime thing, so do it only when it really is right for you.

Within SkyTeam, it wil almost never happen. They don't want to poach each others customers. Perhaps if you move from one airlines hub to a different airlines hub, and can convince them that there is a compelling reason, they might, but I'm not sure about it.