Hello,
VirusTotal can analyse any file type as most of the integrated antivirus engines will inspect any kind of content. Moreover, most of the antivirus engines in VirusTotal do have signatures for malicious Mac OSX files, just a couple of examples:
Taking this into account, not only does VirusTotal scan Mac related files, but we also encourage their submissions.
As to the reliability, it is as reliable as the antivirus signatures of the different solutions integrated in VirusTotal, we are just engine aggregators.
Good morning, virustotal service is suitable scan mac osx *.dmg *.pkg apps and results are reliable or not ?