Does Rest API GW support Cross Account VPCLink ?

No, not directly.

However, you can create VPC link from the API gateway to a VPC within the same account and then connect that VPC to the VPC in the other account using transit gateway or PrivateLink.

Hello ,

This could be helpful: https://docs.aws.amazon.com/pt_br/apigateway/latest/developerguide/http-api-vpc-links.html