No. They should be the same version. Refer to B28294-03 for more details. (see 2.3.2 Oracle Software Requirements)
During a rolling upgrade, you can run different releases of the Oracle database but that should be the only time.
This might be of interest:
Oracle11g Data Guard: Database Rolling Upgrade Shell Script [ID 949322.1]
The first time I ran a quarterly CPU patch on a Data Guard I had to stop for a moment because part of we wanted to run the SQL on the Standby too. Of course Data Guard handles this.
This Oracle note might be is interest:
Master Note for Data Guard [ID 1101938.1]