CeBeDeM only lists 5 symphonies by Ryelandt (op.16 1897, "Esto vir" in D op. 37 1904, op.47 1908, op.55 1912, op.108 1933.) (I'm almost positive sym. 1 has been recorded... hrm.) Yes-
Review of a Jubileum 2-CD set in 2000 that contains a Wilfried Deroo/Stedelijk Conservatorium SO performance (if I interpret correctly) of Ryelandt's 1897 symphony no.1 . also described here
http://www.conservatorium-brugge.be/Aktief.html (so guessing the CD set is still available privately from that source) and the work itself
http://nl.wikipedia.org/wiki/Oeuvre_van_Joseph_Ryelandt here.
Can't find a recording of symphony no2 "Esto vir" of 1904 at the moment. There have been other works recorded besides syms. 1, 3, 4 5 and the quintet - a CD of piano works, a disc available through Amazon.com with the piano quintet and a string quartet also, choral music on Marco Polo, his horn sonata in a collection, choral and vocal music on BIS, and according to allmusic.com also (not sure if this is still available) his violin sonata (ca.1919?) also (another In Flanders' Fields disc from Phaedra, with Victor Legley's viola sonata- a work I've heard on LP; I like Legley's stuff

- and other chamber works by Belgians.)