Hey! Yes, this is definitely possible ..... I've worked with similar Vapi + BYOC architectures.
The direction you're struggling with (Trigger → Vapi → Zoho → Client) is the outbound/webhook leg. The core challenge is that Vapi needs a properly configured outbound call webhook or assistant callback that can fire into Zoho's workflow engine, and most people misconfigure the BYOC SIP trunk handoff at that stage ..... so the call completes on Vapi's side but Zoho never receives the trigger to push to the client.
Quick question: are you using Zoho CRM's telephony integration natively, or routing through Zoho Flow/Deluge scripts as the middleware between Vapi and the client?