Would the static charge from a silicone work mat be dissipated by an ESD mat if placed on top of it?
Would the static charge from a silicone work mat be dissipated by an
  ESD mat if placed on top of it?


Simply, no.


  Would this work?


Even if you put the silicone mat on top of a grounded metal sheet, it can still attract charge to the top side of the silicone mat. That charge is still an ESD problem.