Is it true? Is it the bartender's opinion?
Many things are rude, but not actionable. If you have the money, you are free to consult an attorney, articulate how you have been harmed, calculate the money lost as a result of this harm, and then sue the bartender for damages. It is very doubtful that the cost of the attorney will come close to the award in damages ... if any were to be awarded. Gossips and rumormongers will always be among us.
Usually, the best way to deal with idiots is to ignore them or simply shake your head and smile, telling people that it is simply not true ... assuming it is not true.
This is just one more reason in a list of many as to why being a regular at a bar - any bar - is a bad idea.
- Carl