Can two OpenClaw instances talk to each other local VPS

Yes. There is no built-in “bot-to-bot” bridge, but you can wire it up in a few reliable ways:
Simplest: use a normal chat channel both bots can access (Telegram/Slack/WhatsApp). Have Bot A send a message to Bot B, then let Bot B reply as usual.
CLI bridge (generic): run a script that calls the other Gateway with openclaw agent --message ... --deliver, targeting a chat where the other bot listens. If one bot is on a remote VPS, point your CLI at that remote Gateway via SSH/Tailscale (see Remote access).
Example pattern (run from a machine that can reach the target Gateway):
openclaw agent --message "Hello from local bot" --deliver --channel telegram --reply-to <chat-id>
Tip: add a guardrail so the two bots do not loop endlessly (mention-only, channel allowlists, or a “do not reply to bot messages” rule).
Docs: Remote access, Agent CLI, Agent send.