Spent a little while trying to get the google maps plugin to work, but came across this in the NPM:
Warning"This plugin is not compatible with Cordova-iOS 4.0.0. WKWebView is not supported. They have been huge changes in the API, and due to lack of time, there is no ETA when this plugin will be compatible. PRs are welcome!!"
I’m assuming this is why it does not seem to build for iOS with the latest ionic 2 beta 11 (could be wrong though).
Perhaps a note should be provided here: http://ionicframework.com/docs/v2/native/google-maps/ to alert users of this?
The git is found here: https://github.com/mapsplugin/cordova-plugin-googlemaps