Please goto the free website sponsored by Boston College for advertisements for Irish Immigrants and search for Dennis Falvy. You will come up with Dennis seeking info on his two brothers, Jeremiah and John (the latter I got from a pay site) who came to the US around 1844. Dennis cites Inishannon, Cork and Kinalea and Bandon in his posting.
It is unlikely that the John I found and the one cited on the baptismal records you found are the same person. However, with Irish naming traditions it is likely they are related?