Thanks for your question.
Shunem is an actual place. It is located south-west of Galilee in the tribal allotment of Issachar about 5 Km north of Jezreel. The word Shulamite does not seem to designate a particular place but rather the quality of the maiden spoken of in the Song of Solomon. Here is the definition from Strong's Hebrew dictionary of the word translated Shulamite
in Song of Solomon 6:13, the only place where this term occurs. H7759 shûlammı̂yth shoo-lam-meeth' peaceful (with the article always prefixed, making it a pet name); the Shulammith, an epithet of Solomon’s queen:—Shulamite.
The bottom line is that Shunemites are a group of people while shulamite is a description of the bride in "The Song of Solomon."