Dość zgrabnie ujęto to w "General Rulings":
By default, combat cards only apply to the round in which they are played. Explicit card text is needed to overcome this default. [RTR 19980623]
A maneuver or press gained by a combat card can only be used during the current round of combat. A maneuver or press gained by a non-combat card (e.g., action, equipment) can be used in any round of the combat. [TOM 19960521]