Is there any SEO benefit to anchor text links in PDFs and any tips on how best to optimise a PDF for search?

Hi Friend,
Yes, there are SEO benefits to anchor text links in PDFs. Search engines index pdfs, just as they index html and other text-based pages.

To optimize a PDF for search, I would

-Use text formatting (h1, h2, etc.) to optimize headlines and subheads with keywords
-Use text formatting (bold, italics, etc.) to optimize keywords in body text - use minimally (first-use and for emphasis) and at the top of the document rather than throughout.
-Use anchor text links both to pages within your site and to pages in other sites to build relevancy and authority. Look for pages with high SERPs value for linking. For internal site and blog linking, find ways to link back to the PDF.
-The same keyword relevancy that makes an html page rank better will make a PDF rank better, so make sure you optimize your keywords in the content - but don't overdo it.