Then there's also...

"Dawn on the Irish Coast", a poem by John Locke. a href="thread.cfm?threadid=9739&messages=6">See this Mudcat thread.

"Ireland, My Sireland", a song from the romantic comic opera "Eileen" (1917), music by Victor Herbert, lyrics by Henry Blossom.

A poem by Frank Higgerty, a passenger aboard the RMS Leinster (which was torpedoed and sunk on October 10, 1918 while on its way to Wales from Ireland), also contains the phrase "Ireland my Sireland". Leinster info here