This post hasn't been updated in over 2 years.
ThemeForest has a new feature we hope you will like. We’ve added a new field to the upload page that will now allow you to select certain compatible services in relation to your upload type.
Basically this will allow you to tag your files with different services. So rather than uploading a WordPress theme into a Buddypress category, you would instead upload it to the most relevant WordPress > Descriptive category and then use this field to add in any services the theme is compatible with (i.e. Buddypress, WooCommerce).
At this time, only WordPress themes are completely built out but more will soon follow including Joomla, Drupal, etc…
Update: Mark Brodhuber has provided further information to help clarify.
It’s kind of a mixture of both here’s some more information. Within our current situation if an author submits a theme for a band or artist it would normally go under something like WordPress > Entertainment > … But lets say the theme author decides to integrate social aspects using BuddyPress. Right now the BuddyPress option would take precedence and the file would go under WordPress > BuddyPress. This type of categorization lacks the extra descriptive information gained with our descriptive child categories. Additionally, it limits the theme to only being classified as a “BuddyPress” theme.
Where as under the new method, an author could submit that same theme into the proper category of WordPress > Entertainment > XXX and then attribute it with BuddyPress. But he/she could also integrate other services like WooCommerce for sales. So now you could have a WordPress theme that’s categorized based on description, and then using the Compatible With attribute, it could be sort of tagged with both BuddyPress and WooCommerce.
Another nice thing about this new method is the way in which our items are displayed. If a WordPress theme with both BuddyPress and WooCommerce functionality was submitted before, the author would have to choose one of the three categories to place their theme in. Now it could technically be displayed in all three.
So to answer your question, compatible with should be used when a theme has been built and designed to not only work with the compatible addons selected. But these platforms should also be well integrated and styled to match the rest of the theme.
Just saying something like “tested BuddyPress with this theme and it works” is not sufficient.