How to get status on Alliances?
 

This may be very elementary for FTs: after you achieve a status on one member of an Alliance, do you have to contact other members or join the "alliance" or is this done automatically? How long does it take? Do the other alliance members then treat you like you have status on their airline?

When you earn status with an airline, you also get a corresponding status with that alliance. Your benefits on allied airlines are based on two things: (1) alliance-wide benefits, and (2) bilateral agreements between the carrier you're flying and the carrier on which you have status.

Alliance carriers are supposed to automatically recognize your status and accord you the benefits to which you are entitled.

I'm most familiar with Skyteam, since that's primarily what I fly. So, for example, I have platinum elite right now with NW. That makes me Skyteam Elite Plus. I get the Skyteam Elite Plus benefits (preboarding, priority bag tags, lounge access on int'l trips, etc.) when flying any Skyteam carrier. But if I fly CO, for example, I also get access to domestic upgrades since NW and CO have a special deal in that regard.

It should be automatic.

In oneWorld, your elite ID card from any airline carries a color-coded symbol that reflects your alliance status. There are three oneWorld levels: Ruby (lowest, corresponds to AA Gold), Sapphire, and Emerald (highest, corresponds to AA Executive Platinum). Benefits are generally similar to those noted above for SkyTeam.

Because airlines base status on different parameters, it may be easier to earn a given alliance status level on one alliance member than on another for a particular travel pattern. For example, someone who flies mostly in paid F might earn relatively faster in one program than in another, while the second might be better for someone who flies discount economy. Or one may reward short flights better than another, or whatever. This can be a consideration in deciding which program to participate in within an alliance, though there are generally enough additional benefits to flying on one's "home" airline to make usage frequency the major factor.

Thank you each with the very helpful responses.
From the responses I now understand that within the same Alliance the status is recognized by the other members.
When others are posting questions about status matching: it is really only for airline members of an other Alliance.

Alliance status is recognized by other members of the same alliance, yes. But the benefits of alliance status aren't necessarily as complete as the benfeits of having status with the airline you're actually flying.

Again, using my Skyteam example, if I am plat with NW, I get access to NW's elite phone line and I get unlimited free upgrades on domestic NW flights. If I fly DL, however, they will recognize my Skyteam Elite Plus status and let me pre-board and get priority bag tags, but they will not give me domestic upgrades. If I wanted domestic upgrades on DL, I'd have to have DL status.

Still, airlines within an alliance generally don't do status matching. You are correct that most status matches happen when a passenger decides to switch loyalty to a different alliance.

The purpose of status matching is to encourage someone to change loyalty to another airline, or at least to remove a barrier to changing. In other words, you do it to help one of your competition's best customers ditch them.

Matching status within an alliance would be perceived as an unfriendly act, "poaching," sort of like trying to date your roommate's b/gf. There might be a few situations when it could be OK, such as (to use a oneWorld example) if someone moved from Australia to Chile and found that LAN Chile now made more sense as a home airline than Qantas, but they're rare and would probably call for special treatment.