Why would pcp refer me to hematologist due to elevated protein in blood (elevated gamma globulin)? is this something to be concerned about?

Good question!: Do you have an m-spike detected on your serum protein electrophoresis? If all blood work up is unremarkable and the only thing elevated is the gamma globulin alone- i don't think you need to see a hematologist. However not knowing the rest of the story and lack on information in regard to other blood work- i recommend you to ask this question to your pcp. If m spike is detected- see hematologist.

Further evaluation: There are many reasons for elevation of the serum protein. The hematologist is the best person to guide the work-up to determine if you have something like myeloma or other plasma cell dyscrasia or a non-malignant cause of the elevated protein level.