Contents of PDF on Mobile Devices

PDF on Mobile Devices

PDF or Portable Document Format is anything but "portable" if we are talking about access on mobile devices.
Can the PDF be read by something like VoiceOver on the Mac?

Yes, but you don't have access to the more granular aspects of the documents such as headings, table headers, links and so forth. You either read it or you don't.

A tool such as "Dream Reader" which Is TTS or Text-to Speech for people with learning disabilities removes all formatting from the PDF, keeps it in its own "library" and forces the end-user to use its user interface to access documents.
On an iPhone 4s I tried to open a PDF document in Adobe Reader for the iPhone and iPad and got the message that I couldn't open it on either device. The document was simple and well structured/tagged.