Weirdly, the individual components of your command are working perfectly. For some reason when I put them together it tries to connect to each host. For example, I can run the two lines below without a problem. I only have about 50 servers so at the very least I could run the bottom command once per host. I just need to verify fieldnames for the ones I need. Still experimenting...
(Get-SmHost).Hostname
get-smresources -HostName $hostname -PluginCode SCSQL | Select-Object -Property dbname,dbversion