Original User: bjorn
Andrea, I don't think using a FeatureLayer is necessarily the real solution for avoiding the "ugly white backgrounds".
However, in regards to the topic of this thread.... Annotation Layer are special layers in a Map Service, and the FeatureLayer doesn't currently take advantage of that "special-ness". What happens is that the Annotation Layer returns polygons of where the annotation is supposed to be. To make it work, it is possible to query the annotation layer, then change the geometry to points (instead of the returned extents) and display them in a graphicslayer as TextSymbols with the textAttribute set to the default display field.
Again, while this might answer your question about FeatureLayer using Annotation Layers, I don't think it is the solution to your original problem.