GCP Private Services Connect (Similar to AWS Private Link) is not available yet for Elastic Cloud, it is however on the roadmap as it is a highly requested feature. I do not have and ETA , keep your eyes open I am sure we will publicly announce when it is available.
You can use traffic filters to make sure only the traffic from your endpoints can access the elastic cloud deployments, but I understand that it's different than what you are looking for.
We do know if you deploy elastic cloud in the same region as your resources that are accessing it even though the elastic Cloud IP is public the traffic never leaves that region.