The suspension follows a traffic incident in the United States in April.
As part of the suspension there will be a significant reduction of Matthew's financial support as a member of the program.
The final three months of the six month sanction will be suspended pending the status of any legal proceedings and Matthew being in a position to resume his place in the squad.
In addition he will be required to complete agreed community work that will include addressing the GA National Squad and undergoing a counselling/education process to ensure that a similar incident does not occur again.
Golf Australia CEO Stephen Pitt said "Golf Australia will continue to work closely with Matthew and both parties are committed to ensuring that he fulfils his potential as a professional golfer and as a role model for future golfers."