Well AFAIK the programming talk board is for other languages including C++. So regardless you would be safe posting there.
That said...
I think you really have to make a judgement call. If your game/engine is really awesome, and you post it here, most people will be more into the game and not bother about why or where it's posted.
If on the other hand, the game is less than awesome, and you post it in Geek Culture, Just be prepared to get some flames, a locked thread.
Either way, I wouldn't post it in the W.I.P. boards as that area is considered an area that is solely for TGC products. And people generally don't want to see games made in other engines/languages littering around regardless if they are good or bad.
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I'll have to go over the entire AUP to see how strict this area is. Becuase personally, it wouldn't bother me if someone posted a project they were working on. Even if i didn't like it. But then again I'm not TGC nor am I a MOD, and I can't speak for the rest of the community. So let me read the AUP and I'll see if it gives any better insight.
EDIT
K i just read over the entire AUP, and I didn't see anything against posting a porject done in another language. So as long as make sure you adhere to all the other items in the AUP you should be ok, to post your project here in Geek Culture. After all games & game making are a part of Geek Culture. Just make sure that none of your assets are stolen, and isn't overly graphic (especially sexually; it would seem shooting people is considered more family friendly than any form of nudity).
So good luck, just remember if it's aweful people here are going to let you know it without holding back.
here's the rest of the AUP
http://www.thegamecreators.com/?gf=aup#forum
"When I look at that square... I wish FPSC noobs would stay on their side of the forums and stop polluting these boards." - Benjamin