This is what ST_DumpPoints is for:
SELECT ST_X((dp).geom) AS lon, ST_Y((dp).geom) AS lat FROM ( SELECT ST_DumpPoints( ST_GeomFromTextST_GeogFromText('MULTILINESTRING((-121.382859 41.9831,-121.382849 41.983485))')::geometry ) AS dp ) AS foo; Output:
"lon";"lat" -121.382859;41.9831 -121.382849;41.983485