I just tried and I can confirm, that promo codes can be reviewed on the US Appstore again using an iDevice! We will put Promo Dispenser back into the state, where users have to review apps on the Appstore again for getting a new promo code.
That was always the case if you posted a review very soon after the code was redeemed - like an hour. Did you wait longer then that?
Believe me, I tested everything, because it's my "job" and there was no one hour case. On a mobile device you got immediatelly the message "you have to own this item". If you redeemed and reviewed on a PC through iTunes, then you could review, but not on an iDevice. But almost nobody knew that. Now you can review again everywhere.
Figured I'd let everyone know that now, after the lockout, you can no longer review promo codes except within the hour. . This no longer works.
I tested things out. It seems that my old promo codes for the Mac App Store are now usable for reviewing... but it didn't work with the iTunes App Store.