Spain has an eternally schizoid relationship with trains. They're a badge of honour on one level, but when it comes to information management and distribution, it's welcome to 1999.
I did ask someone I know who works in Renfe traffic management a year or so back about this. There was nothing then and I don't think the situation has changed. The only thing that's even vaguely useful is that the Adif site - which is pretty feeble - sometimes announces platforms ahead of station PIS - and even that's only vaguely useful sometimes.
And it's not just there's no Horarios de trenes de verdad. There's not even an equivalent of National Rail!
DP