I'm currently looking for an easy way to deploy to a remote websphere server using maven from OSX. I haven't found that much online about this topic. There seems to be a liberty-maven-plugin, but I'm unsure if that can do remote deployment.
No, the Liberty Maven Plugin does not currently support remote deployments but there is an Issue open for it:
https://github.com/WASdev/ci.maven/issues/16
It might be worth following that issue and adding a comment to indicate it is something you are after.