It should be indexed in minutes normally.
If you have some strange delays, please do this:
Try to open WP Admin on the WPFTS Settings page for some time and notice if the number of indexed documents increases. If not, it should be a bug in the code that appears in error.log - please check this file if there are some error messages.
Try to follow this recipe to fix the DNS problem (normally indexing should go transparently without WP admin open).
Let me know what you found, I also could help you via the short TeamViewer session.