Hello again Eileen!
The marriage records for Doon parish start in 1839 http://registers.nli.ie/parishes/0260 and if that was Bridget's parish likely the marriage record is not available.
I assume you located the 1901 and 1911 censuses for John Commins/Cummins and family and know that John died in 1909. His death record and Bridget's are below. I also see a death index record in the Tipperary registration district for a Patrick Cummins age 60 who died in 1868. The images for 1868 deaths are not available at this time (images start in 1891). The Tipperary registration district is large so this could also be a different Patrick Cummins. Also, it is possible that your Patrick died before civil registration began in 1864.
Let me know what questions you have.