Cannot use an annotation class as the input to the Feature to Point tool and then use this output feature class as the target layer for the Spatial Join tool in ModelBuilder (or Python) unless these two processes are run separately. (In which the Feature to Point output is saved to a hard location on the disk and not just in memory.)
Use the Joins and Relates > Join > Join data from another layer based on spatial location.This workaround is only sufficient if not trying to use this process in a model (which requires using the GP tools).