& I may well (probably will) be totally wrong (we don't utilise NOM & are currently ony running at 6.5.4 so no experience in any of the above
;) ), but looking at the odd TechNote & Admin Guide I would suggest that the answer to this is no (?)
DOCUMENTATION: Which versions of NetBackup Operations Manager (NOM) can manage which versions of NetBackup master servers?
http://seer.entsupport.symantec.com/docs/295597.htm
Seems to indicate that NOM can only monitor at its own patch release or below (except for 2 instances: prior to 6.0MP6 and 6.5.4/6.5.5 - so there may be hope?)
DOCUMENTATION: NetBackup multi-version co-existence: what combinations of 7.0, 6.5.X, 6.5, 6.0, 5.1, 5.0 client, media, and master servers are compatible?
http://seer.entsupport.symantec.com/docs/264767.htm
"...
The NetBackup Operations Manager (NOM) version may be the same or higher than the version of the NetBackup server that is being managed, providing everything is at least NBU 6.0MP5.
..."
Which confirms the above also i.e. only at its own release or below.
From the
OpsCentre Admin Guide:
"...
When you upgrade from NOM or VBR to OpsCenter server, the OpsCenter installer only stops the existing NOM or VBR services. It does not uninstall your existing NOM or VBR installation. If you have not uninstalled NOM or VBR, you can use your older installation.
..."
& then goes on to explain the process which is what you've probably already done.
It does go on to say:
"...
In case domains are not visible on the logon page and you cannot log on to NOM, you must reinstall Symantec Product Authentication Service that was shipped with your NOM version. See the NOM documentation for more information.
..."
but this does not indicate (nor deny) its ability to monitor a NB7 environment!!
Sorry I can't provide a more definitive answer, but I'm sure someone out there can