Because homespun has two meanings, it’s still a little hard to tell without more clear context to whether the person was referring to the Colombian employees or American expats working for the company.
Two meanings given in the OED are:
1. Cloth made (spun) at home
2. “Simple and unsophisticated” which comes from the lesser quality of homemade cloth.
Because of the first meaning of homemade, he could be referring to American employees. But because of the second meaning it could be an imperialist, kind of discriminatory way to refer to Colombians.
I’ll copy my comment here for completeness.
I had a second thought that it could be generically referring to employees that they had trained and had been there a while as opposed to employees that were trained somewhere else and hired after training. The “spinning” being the training and development of the employee’s skills.