Workspace users with the Business Standard plan have access to Gemini Advanced, which is Google’s AI offering via the Web interface and mobile apps. This does not include API usage, AI Studio, Gemini CLI, etc. — all of which are of course available, but must be paid separately or used in the free tier.

In the case of Gemini CLI, it seems Google does not even support Workspace accounts in the free tier. If you want to use Gemini CLI as a Workspace customer, you must pay separately for it via API billing (pay-as-you-go). Otherwise, the alternative is to login with a personal (non-Workspace) account and use the free tier.