FYI, I am having the same problem with my Samsung Galaxy Tab 7 Plus:
ANY Android app that have a tablet-optimized version in a single app (no 2 separate versions) will not show the tablet version when installed in my Samsung Galaxy Tab 7 Plus.
I tested this with most popular tablet-optimized apps, such as Mint and TripAdvisor and same problem. HOWEVER, in my friend's ASUS Transformer tablet, it work just fine.
I believe this have issue with the screen resolution, since my Samsung Galaxy Tab 7 Plus is 1024 x 600, and these apps does not recognise these resolutions and hence, just defaulted to the "phone" mode, judging by the response from Mint.
This is just a piss-poor planning on the Android OS design...