I realize that many on this list have likely applauded the NetworkManager package split that removed wireless stuff into its own package, NetworkManager-wifi, because for wired workstations and servers it might be desirable to not have any wifi software installed. And I believe it was a sound technical decision to do the split.
However, in doing a fresh installation of what most call CentOS 7.2, or 7.2.1511, I ran into a real issue that required a bit of deep-diving to find, and a simple 'yum install NetworkManager-wifi' to fix. (although my actual 'yum install' command included the full path to the actual RPM on the install media.......)
I have a personal workstation at home, a Dell Optiplex 745 with a Core2Quad Q6600, that is on the other end of the house from the router. While I could run cat5 to the location, it would involve quite a bit of labor, and I have a known-supported USB wifi nic based on the ralink rt3070 (cheap, but works well), so why should I run the cable when wifi should work well? Especially given that the Dell is not going to be there for very long it wouldn't make sense to run cable.
Anyway, I configured the wifi network during installation (I actually am growing to like, even prefer, the hub-and-spoke anaconda), it associated with the WPA2-protected AP, grabbed an IP address, and all was good. Did the install; no errors.
I rebooted, and now there is no wireless. At all. Doing a bit of troubleshooting shows that the kernel sees the NIC, but NetworkManager shows it as 'unmanaged' ('nmcli d' is the command to use from a shell). So I warmed up my google-fu on my laptop and finally tracked it to a post that mentioned having to install NetworkManager-wifi. Sure enough, on the workstation NetworkManager-wifi was not installed. I mounted the USB install drive's ISO partition and manually installed it, restarted NetworkManager, and it now works just fine.
But why did anaconda not select the NetworkManager-wifi package to be installed if a wireless network connection was configured in the installer? Anaconda should have some way of forcing the install of the appropriate NetworkManager modules if those are needed (but only if they are actually needed) for a configured connection during install.
I can file a bugzilla, but I thought I'd post about it here first to get an idea of which package in which to file the report, since it's not a bug in NetworkManager-wifi. Anaconda? (that is my first impression of the proper place).
So if you have this situation arise where wifi doesn't work after install of current CentOS 7(1511) but does during install, manually install NetworkManager-wifi from the install media and that should clear it up.