I'm on my final year of an Architecture degree and I'm not entirely sure of the importance of the majority of Architecural technicalities with relation to game art creation. Personally, I've found what Flava-Fly said about exploring various artistic backgrounds has been a real help. So in that regard, Architecture is another notch on the belt so to speak.
Studying architecture visually is probably gonna benefit you most I'd say. There's a LOT of structural details and sciences involved in architecture, things like structural loading, and a lot of 'behind-the-scenes' stuff you're likely to never need for game work. For example, you're unlikely to ever need to know the exact dimensions required for a lintel over a certain sized window... however there are of course examples which would help. Like the minimum tread-depth on a staircase, or the number of supporting members on a ceiling, these things will help add realism and believability to your scenes.
Is a massive book, a great visual reference on some fantastic architectural design. It covers a lot of details and has floor plans of a lot of the buildings featured which is a nice insight into their creation.
One other thing which has helped me a lot (despite it not really showing in my portfolio) is learning about lighting. Knowing how much light a room should have depending on it's purpose, and the way lights should be placed to achieve that, as well the technicalities of different types of natural / artifical light, it's a subject that should help quite a bit with 3D work. Also a lot of studios seem to list a good understanding of light/lighting a preference on their environment art openings.
Hope that helps a bit.