I believe you have to link your easports account with your gamertag/PS3 Id in order for it to know what system you have. That might just be for if your team is set to private though (so it can know that it's your team).
You can tell if your account is linked by what's in parenthesis after your screen name on easports (if your not linked it will say "CPU" or "Web" or something. If you are linked it says "Xbox 360" or "PS3."
Here's a link to start setup for linking the accounts (if you haven't already):
http://support.ea.com/cgi-bin/ea.cfg...2552&nextlink=
Once you are linked, the in-game search function to default to searching under your Gamertag/ID. Just hit "search" and you should be set.