Can I be fired or disciplined or retaliated against if I type on Facebook my job is being a dick literally just those words and nothing else used?

My situation is I work for a pizza delivery company that has no formal HR it's literally just the owner and a general manager. Recently my personal vehicle during work hours experience the mechanical breakdown and I was taken off the work schedule during which time my vehicle was brought into the shop and while it was in the shop a freak accident happened which cause my vehicle to become damaged at the shop and now I'm waiting for insurance to either total my vehicle or repair it. Now the insurance company was kind enough to give me a rental car for at least 5 days in which I contacted my manager and told them that I would have a vehicle and be ready to work until I can procure another vehicle of which I was told that they were all set on the schedule it didn't have any room for me. I had posted a short frustration rant on my Facebook which was set for friends only not public and a few days later upon getting my last paycheck, i was told the owner read my post and wasnt happy with me.