If anyone else gets the following error on trying to use the 64 bit version of phantomjs binary..

./phantomjs: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
yum install zlib.i686

Try using yum to install the following packages..

yum -y install glibc.i686
yum install zlib.i686
yum install fontconfig freetype freetype-devel fontconfig-devel libstdc++
yum install libfontconfig.so.1
yum install libstdc++.so.6

Worked for myself.