I was sent to this question by a coworker and realise that it's been posted quite a while ago. Anyhow, since this might help other people in the future...here we go:
When it comes to the marketing website for an app, the European authorities (more specifically a pan-European privacy thinktank) say this:
The Working Party recommends that information about personal data
processing is also available, and easy to locate, such as within the
app store and preferably on the regular websites of the app developer
responsible for the app. It is unacceptable that the users be placed
in a position where they would have to search the web for information
on the app data processing policies instead of being informed directly
by the app developer or other data controller.
Terms follow a slightly different logic. Apple provides a default EULA doc for all downloaded apps. If your site has things going on in addition to being a mere marketing page, then you might want to look into creating a proper terms doc. There too though, if you cover some basic requirements coming from Apple's side, you should be able to combine them into one document reigning both the app and the site.
Hope this helps!