Are Roman Catholic priests ever addressed as pastor?
The short answer is: Yes, but not in English.
Priests who are pastors, in English speaking counties are often referred to as pastors. The assistant pastor is called either the assistant pastor or the associate pastor. The signage in front of many Catholic churches bares this out.
However, it is also commonly accepted that pastors in English speaking countries should be addressed as father. I have never heard of a parish priest being referred to as Pastor "X" by any member of the faithful in English.
The title of Father is very commonly given to Secular Priests, as well as to Priests of Religious Orders and Congregations. - Ecclesiastical Addresses (Catholic Encyclopedia)
This is not so true in the French language, where priests who are pastors of a parish church are commonly referred to as Monsieur le Curé.
"Monsieur le Curé", being used for all parish priests. - Ecclesiastical Addresses (Catholic Encyclopedia)
Most Catholics have heard of St. John Vianney also known as the "Curé d'Ars". In France Parish priests are quite commonly called Monsieur le Curé or as one would say in English "Mister [the] Pastor".
St. Jean-Baptiste-Marie Vianney, T.O.S.F. (8 May 1786 – 4 August 1859), commonly known in English as Saint John Vianney, was a French parish priest who is venerated in the Catholic Church as a saint and as the patron saint of parish priests. He is often referred to as the "Curé d'Ars" (i.e. the parish priest of Ars), internationally known for his priestly and pastoral work in his parish in Ars, France, because of the radical spiritual transformation of the community and its surroundings. Catholics attribute this to his saintly life, mortification, persevering ministry in the sacrament of confession, and ardent devotion to the Blessed Virgin Mary. His feast day is 4 August.
The YouTube video in French on the life of the "Curé d'Ars" clearly bares this out: Le Sorcier Du Ciel. Although it is an older movie and in black and white, it is quite enjoyable to watch, especially if you understand French. It does have English subtitles for those interested.
While living in France, I would quite often addressee Catholic priests who were pastors as Monsieur le Curé or more affectionately as Mon Père.
The word Curé in French referrers to priest who is charge of a parish.
Curé
Prêtre qui a la charge d'une paroisse dans la religion catholique.
Synonymes : abbé, prêtre
Traduction anglais : parish priest