I could not find any phing plugin for netbeans
Give the Ant plugin try. Because the syntax is very similar to ant you'll at least get nice target overview in the Navigator instead of the default xml structure overview. Better than nothing.
http://plugins.netbeans.org/plugin/47165/phingking There was not a plugin before but now there is PhingKing
NetBeans 8.1 Beta comes with phing support: https://blogs.oracle.com/netbeansphp/entry/phing_support_added
I've already tested it and it works quite well.