Hello, Mikeswalkabout.
Welcome to Apple Support Communities.
From what I've read is that some of your apps aren't being displayed under Siri Faces. You can check out this article for information about Apple Watch Faces with Siri: Apple Watch faces and their features
"Siri
With this face, Siri takes a look at your day and displays information that’s timely and helpful. It might be your next appointment, the traffic on your way home, or the score of a game played by your favorite team, and you can tap to get more information. You can also turn the Digital Crown to scroll through your day.
- Customizable features: Color
- Available complications: Activity • Alarm • Air Quality • Audiobooks • Battery • Breathe • Calculator • Calendar • Cellular (cellular models only) • Cycle Tracking • Date • ECG (not available in all regions) • Favorite Contacts • Find People • Heart Rate • Home • Mail • Maps • Messages • Moon Phase • Music • News • Noise • Phone • Podcasts • Radio • Rain • Reminders • Remote • Siri • Stocks • Stopwatch • Sunrise/Sunset • Timer • UV Index • Voice Memos • Walkie-Talkie (not available in all regions) • Weather • Weather Conditions • Wind • Workout • World Clock".
Any other apps not listed here won't be available and if they are third party apps, you'll need to reach out to the App Developer:
How to contact an app developer
Best regards.