Problem!
If your posts do not show up, when posting from your iPhone app, here's why: Using the "iPhone" word triggers a spam warning (yes, many spammers have offered iPad/iPhone gimmicks in the past, but that's another story).
Solution?
Change or remove the annoying signature in the app, that says: Sent
from my iPhone using Motorcycle.com Free App.
Otherwise, just wait 'till your post gets moderated, although I strongly recommend you do not wait.