Bard with pro is apparently text only:
> Important: For now, Bard with our specifically tuned version of Gemini Pro works for text-based prompts, with support for other content types coming soon.
https://support.google.com/bard/answer/14294096
I'm in the UK and it's not available here yet - I really wish they'd be clearer about what I'm using, it's not the first time this has happened.