Are the host names those of the host targets exactly as they appear in EM? Are they resolvable using nslookup on the oms as they are specified? IF you are not using FQDNs and DNS all end points must be configured to be able to resolve the other end.
Also, how long have these hosts been under management by EM? If they are very new, it could be some necessary collections have not happened yet.
Looks like it might be bug 15982024 where the target is already part of a cluster. Can you check your unpromoted targets (Setup -> Add Target -> Auto Discovery Results -> tab Agent Based Targets) and see if a cluster on either of those hosts is already discovered but not yet promoted. If so, you can try to delete that discovered cluster, and retry the cmd.
Log File Locations
The following examples show possible log file locations:
If you do not specify a configuration directory when you run the
-diroption is omitted), EM CLI assumes the
.emcliconfiguration directory is located within your local home directory. The log files are placed at the root level of the
.emclidirectory must be local (not mounted remotely).