I knew I was taking a chance as the repo is for RHEL 6 and the machine is RHEL 5, but I figured "it's php, what can go wrong?" This is what went wrong:

owncloud-6.0.1-5.1.noarch from isv_ownCloud_community has depsolving problems
--> Missing Dependency: php-pear-Net-Curl is needed by package owncloud-6.0.1-5.1.noarch (isv_ownCloud_community)
php53-common-5.3.3-22.el5_10.x86_64 from rhel-x86_64-server-5 has depsolving problems
--> php53-common conflicts with php-common
owncloud-6.0.1-5.1.noarch from isv_ownCloud_community has depsolving problems
--> Missing Dependency: php-pear-MDB2-Driver-mysqli is needed by package owncloud-6.0.1-5.1.noarch (isv_ownCloud_community)
owncloud-6.0.1-5.1.noarch from isv_ownCloud_community has depsolving problems
--> Missing Dependency: php-pear-MDB2-Driver-mysqli is needed by package owncloud-6.0.1-5.1.noarch (isv_ownCloud_community)
owncloud-6.0.1-5.1.noarch from isv_ownCloud_community has depsolving problems
--> Missing Dependency: php-pear-Net-Curl is needed by package owncloud-6.0.1-5.1.noarch (isv_ownCloud_community)
Error: Missing Dependency: php-pear-Net-Curl is needed by package owncloud-6.0.1-5.1.noarch (isv_ownCloud_community)
Error: php53-common conflicts with php-common
Error: Missing Dependency: php-pear-MDB2-Driver-mysqli is needed by package owncloud-6.0.1-5.1.noarch (isv_ownCloud_community)
You could try using --skip-broken to work around the problem
You could try running: package-cleanup --problems
package-cleanup --dupes
rpm -Va --nofiles --nodigest

Owncloud install is now on hold...