I think I found their marriage info at this site

http://www.rootsweb.ancestry.com/~palackaw/

Peter Wiever wed Magdalena Rusickinte in 1898 in Lackawanna county PA. It is listed in book #49 which begins with Nov 1898, so they were wed in either Nov or Dec of 1898.

But I still could not find them in 1900 census.