The question should be reworded to clarify exactly what you are asking. The current wording is ambiguous. You seem to indicate that you can't find documentation for getting CentOS connected via wireless on your PI Zero? Do you already have CentOS (or some variant of it) running on your PI?
CentOS does not support the ARMv6 architecture, which is what the PI Zero and PI 1 use. Fedora is similar to CentOS, and there is a third-party Fedora port for PI called Pignus. This explicitly supports ARMv6. If you wish to install a CentOS-like OS, take a look at this. It is still in Alpha release. It should be noted that this is not considered stable and should not be used for production systems.
For getting the standard headless Jessie Lite up and running, take a look at
this website. Basically you need to edit
/etc/wpa_supplicant/wpa_supplicant.conf using a text editor (vi/nano) with sudo permissions. Append this to the wpa_supplicant.conf file:
ssid="Your Network SSID"
psk="Your Network Password"
I'm assuming that you have some decent technical experience because you are not running a default config/OS on your PI 3, otherwise I would have given more explicit instruction.