I don't have access to Apple Photos, so I can't test it but the command you list will copy to XMP tags. MOV/MP4 files don't support IPTC and I'm not sure of the status of EXIF tags in video files. Odds are, Apple Photos doesn't read those tags.
If Apple Photos has the ability to write the title, I'd suggest writing to a test file and then using exiftool to see what is written. If it doesn't, I'd suggest trying '-basename>Quicktime:title' and seeing if that works.