Can Yosemite Backup perform cross-platform/cross-file system backup and restore jobs?
Yes, so long as you deselect the “native data stream format” in the Advanced options section on the “Options” tab of the properties of the backup job. You must do this prior to running the backup job and backing up the files. Yosemite Backup is a backup application and any cross-platform restores should be tested to ensure your desired functionality.