Is St. Philomena still a saint?

Yes and no to your question.

St. Philomena is a very unusual case. On May 24, 1802, in the Catacombs of Priscilla, a tomb was found containing the bones of a girl about 14 years of age. On top of the tomb were three tiles which were inscribed with "Pax Tecum Filumena" "Peace with you, Philomena"). Also found was a small glass vial containing dried blood. All this seemed to indicate that this was the tomb of a girl named Philomena who was martyred.

The remains were boxed and placed in storage until 1805 when a priest named Francesco De Lucia requested relics for a new altar for his church in Mugnano del Cardinale. He was given the remains of Philomena. Soon after, devotion to the little saint spread throughout Europe, especially in Italy and France.

Miracles began to be reported and even St. John Vianney made note of a miracle and built a shrine to her in his church in Ars. The only evidence we have for Philomena are her bones, the vial of blood and the inscribed tiles. The information about her life came from private revelations to two individuals where her life and death are spelled out.

Pope Gregory XVI gave permission on January 13, 1837, for public veneration of Philomena in some limited places but not throughout the Church. This was interpretted by some as an act of canonization for Philomena, which it was not. The name of Philomena was never included in the Roman Martyrology, the official list of saints recognized by the Catholic Church.