Keep in mind that it's not possible to sync events on secondary calendars at this time. Google Calendar Sync will only sync events from your primary Google Calendar and your default Microsoft Outlook calendar.
Google Calendar Sync: Getting Started
Google Calendar Sync allows you to sync events between Google Calendar and Microsoft Outlook Calendar. You'll be able to determine the direction of information flow, as well as the sync frequency.
it's not possible to sync events on secondary calendars at this time. Google Calendar Sync will only sync events from your primary Google Calendar and your default Microsoft Outlook calendar.