You do different chest exercises for each workout within the 3 day week. Week One is straight sets, week two is antagonist sets. For weeks 3 and 4 you need to have different chest exercises than weeks one and two. (Hope that made sense)
For TBT to work you need to utilize all chest angles and use dumbell/barbell options as well as wide grip dips.
And as far as the antagonist supersets, for example you'd do chest, rest predetermined time, back, rest, chest. . until you have completed the desired # of sets.
I hope all of this made sense because TBT is an awesome program.