This is less a question and more an answer to a problem I was having that I found an answer to elsewhere so I thought I'd post it here for others.
I have a 580 book in InDesign CC with a TOC and automatic bookmarks for all the chapters and subsections across the book's 10 documents. The bookmarks work perfectly in InDesign but when I exported to PDF (interactive, with bookmarks included) only the bookmarks within the first document worked. All the others were listed but went to the first page, not their correct page.
I found this link which gave me the answer: http://forum.rpg.net/archive/index.php/t-319074.html
Basically, don't mess with the TOC after it has been created.
I had made a few tweaks to the TOC after creation, such as deleting an extra tab character, applying character styles, inserting column breaks.
Having read the suggestion at the link above, I fixed the extra tab and a couple of other minor text edits at the source paragraphs, tweaked my TOC paragraph styles to adjust spacing and recreated the TOC. It exported perfectly - working bookmarks across the whole book. So then I went back and did a bit of experimenting and found that I could apply colour to the TOC text by directly applying swatches to selected text and it still worked. To get rid of entries that I didn't want in my TOC and to get column breaks where I wanted them, I changed my text frame to single column and threaded multiple single-column frames of varying height on and off my page. This also exported perfectly. I didn't try applying character styles or making any edits to the text.
Hope you find this useful.