No, there is no need to.
No there is no need, while Stores are unik for the whole system. So a collection filtered by store is only a subset of a collection filtered by website.
I actually never used the website filter, because there wasn'T any need to do so.
But lets see a short sceanrio:
Applying the method
addStoreFilter(StoreView A) will result in a collection with 2 items while the same collection with
addWebsiteFilter(Website A) will get a collection of 4 items.
hope that helps.