Here is a much shorter method… Thanks to guideance from Norman
let xcodePlist = UserDefaults(suiteName: "com.apple.dt.Xcode.plist")
if let retValue:AnyObject = xcodePlist!.object(forKey: "IDETemplateOptions") as AnyObject? {
// print("Value : \(retValue)") // if you want to see other "keys"
let bundleIDPrefix : String = retValue["bundleIdentifierPrefix"] as! String
print(bundleIDPrefix)
} else {
print("error")
}