Is this Sphinx server set up separately to your local Thinking Sphinx configuration? Thinking Sphinx expects certain attributes to exist in the Sphinx indices (and, as you've discovered, certain naming conventions). It also needs to be using the same data source as your ActiveRecord models.
In short - if the Sphinx configuration isn't generated by Thinking Sphinx, I'd be extremely hesitant to mix it and Thinking Sphinx together.
But otherwise: the full stack trace of the NoMethodError would be useful.