You can do that in Ubuntu because they ship vim 7.4 on their repositories. It will be that simple on RedHat also if they would have shipped the new version. But, as you have seen, they don't.
RedHat pretty much doesn't upgrade any software to a new major version. This is why redhat6 has a lot of old software (ruby, python, the kernel and almost anything else).
With a little work (not a one liner) you can install vim 7.4.
What you want to do is search first in a site like http://rpm.pbone.net. But this is a little advance for you, I think.
I did the search for you and found this: http://rpm.pbone.net/index.php3/stat/4/idpl/31369581/dir/centos_6/com/vim-enhanced-7.4.629-5.el6.x86_64.rpm.html
From one of those mirrors, you can install directly the package:
yum install -y ftp://mirror.switch.ch/pool/4/mirror/centos/6.7/os/x86_64/Packages/vim-enhanced-7.4.629-5.el6.x86_64.rpm
Off course, this comes with all the caveats of installing software from some random site on internet.