Does Eraser 5.7 erase a files alternate data stream?

It does. Although, if the data stored on the alternate data stream (or any other data stream in a file for that matter) gets written to the NTFS journal file, this won't do you much good. The article you mentioned does not take this into consideration at all, which probably affected some of the tests conducted by the author.

In other words, it is possible that overwriting does not remove all traces of file data when NTFS or other journaling file systems are being used. There is nothing any application can do about it. Users concerned about their security should store their data on an encrypted partition instead.