Technically the bulletin plays apply only to the play situation in question. But, they are insights into the rules committee way of thinking, so I think they are valid as long as the rules they depend on don't change and the secretary of the committee stays the same.
It can be very annoying trying to figure out if a particular rules issue is covered with a valid play situation ruling or not. I once started going through all bulletins and making short metadata out of them so I could then easily search for "passing plays involving the sideline", for example. But then I got bored and the list is now very much out of date.