This repo does provide the 5.5 packages of PHP, you just need to know how to tell it that that's what you want.

Setting up repo, if not already

$ sudo wget http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm $ sudo wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm $ sudo rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm

This will upgrade PHP from 5.3.3 to PHP 5.4.24 (15. January 2014).

$ sudo yum –enablerepo=remi update -y

If you want the newest PHP, version 5.5.x you must run the following command:

$ sudo yum –enablerepo=remi,remi-php55 update -y