Some evidences support this question.
Firstly, in the second mission (The Place of Chariots), Beta wing is ordered to scan NTF cargo boxes, which, mysteriously, is unscannable. It is possible that Allied Command jammed the devices of those Terran fighters or something, since they didn't want to reveal ETAK yet; if ETAK is immediately discovered, Command'll have to order the Alliance to diminish this project, or else Command will sound ridicolous. Command only reveals it later in the game, once it's already completed and ready for use on the Shivans.
Secondly, in the third mission (The Romans Blunder), Alpha 2 argues that the Alliance hasn't set a blockade on the node. It seems somehow obvious that Command's reply is fake (they say that the blockade has been sent elswhere in the system to do important business), since swerving away from the destruction of a hostile flagship is an illogical tactic to perform.
Moreover, Bosch actually says his famous line:
"I regret your efforts to intercept us have failed, pilots. You would be well advised to question the wisdom of your leaders.
Bosch regrets that Alpha and Beta wing have failed in their mission to intercept his ship, most probably, since Command
didn't want the Iceni to be destroyed in the first place. Bosch advises the player to "question the wisdom of the leaders", which further supports the theory that Command intentionally allowed Bosch to succeed in his communication of the Shivans. To "question the wisdom of your leaders" means that Command's wisdom may have been mistaken in the eyes of mere pilots, and that the real information, which was to allow Bosch to succeed, is top secret.
Why top secret? Of course, Command wouldn't want the populace to find out that they're actually supporting the enemy. To explain why communication with a nemesis that attacks for no reason, and killed billions of innocent lives, will be completely unheard of and tremendously hard to explain.
These are two logical evidences that I've picked up on supporting this statement of Command allowing Bosch to use his ETAK.