You can setup a rule in Layers that will capture the Style feature but it won't differentiate between Style curves and Style surfaces. Make sure you setup the rule by selecting the following:
Look for: Feature
Look by: Feature
Since Style features are normally "super features" with best practice being to combine curves and surfaces created using ISDX functionality being in a single feature (allows you to dynamically update things by pushing and pulling on the curves) I don't know of any way to separate the curves from the surfaces.
If you are creating Style curves for use with Boundary Blend surfaces (each Style curve is an individual feature in the same manner as datum curves) then this layer rule will work for you