Is Coworker bullying considered hostile environment?

My coworker has been making fun of me because I come late. It has gotten to a point where my team members make fun of me every now and then and started calling me 1030. When I was hired, my manager and his boss were ok with the timings. Also flexibility and work life balance is a company culture and there's nothing different that I am doing. I have been a top performer and I feel I am bullied because my team member is jealous of me. Everyday I go to work with a fear of what my co-worker will comment on me. I have completely lost focus of my work and its affecting my productivity. Can I sue my employer for a hostile work environment? BTW I already sent a complaint email to HR manager and waiting to hear back. Pls advise.