Yep, 04/05 WRX and STi hoods are the same. If you're asking if the 04/05 WRX and STi hood scoops are interchangeable, yes they are. The 04/05 STi scoop is bigger than the 04/05 WRX scoop, so many people upgrade from a WRX to an STi scoop to allow more air into the system. Like Joshua said, the STi scoop also comes with a splitter which routes air a little more efficiently too.
The 04/05 STi hood scoop is sometimes known as the "snow shovel" scoop - for obvious reasons