How to get Siri to list all relationships

The Reminders application does something similar, it knows three locations: Home, Work, and Other. When you assign a location to a reminder, you are presented with the current location, those 3 previously mentioned locations, and a "Choose Address" option. The 3 locations are taken from the address book's contact information for yourself. The contact that represents yourself is determined by the setting under Settings > Safari > AutoFill > My Info.

I'm guessing that Siri uses the same My Info setting to determine locations such as Home.

Note that the name of a contact has no effect on the Reminders app. Even if you have a contact named "Home" it will not present this as a default address unless the contact is also assigned to the My Info setting.

Update: Siri has its own My Info setting which is the exact same one accessed in Safari (i.e. they always have the same value).

You can create iCloud contacts that merge with your GMail contacts. The iPhone will collate the data from both the GMail contact and the iCloud contact. I have this enabled for Hotmail:

1. Enabled iCloud syncing for contacts.
2. Open Contacts.
3. Press the back button (top-left) until you reach Groups.
4. Open All iCloud or All from My PC.
5. Create a new contact for your wife. Include her full name and phonetic name.
6. Press Done.
7. Scroll down and check that Linked Cards shows an entry for Unified and GMail. Press Unified.
8. Now you can see how your wife's information combining the GMail information and the iCloud phonetic information.