I recently added a second local vault to 1Password 6.8.8 on MacOS 10.13.2. I checked the new vault in the WLAN Server settings. However, 1Password 7.0.BETA-3 on Android only syncs the Primary Vault for me, the new vault does not appear in the Android App.
1Password Version: 7.0.BETA-3
Extension Version: Not Provided
OS Version: Android 8.1
Sync Type: Not Provided