As stated, Teamwork allows you to coordinate with any other group. However this may not suit all games or character concepts.
I had the idea that when you buy Teamwork skill, you state which group/team/individual you learned how to team with, and if you want to get that benefit with anyone else, you have to buy a Combat Familiarity.
Combat Familiarities can be bought for: Military Groups (e.g. Marines), Super groups (e.g. Frivolous Five), an Individual (Captain Amazing) or even a Martial Arts Style (that you have also purchased. e.g. Kung Fu)
Combat Familiarities could also have 'Analyze Style' type benefits.