By Patricia Reaney NEW YORK (Reuters) – American actress Amanda Bynes, wearing a long blue wig and sweat pants, appeared briefly in court on Tuesday on charges of marijuana possession and throwing a bong out a window and a judge postponed her case until September. Bynes, 27, made no comment during the hearing but has previously denied the charges of possession, reckless endangerment and attempted tampering with evidence. All the charges against Bynes, who has made headlines in recent months for erratic behavior, odd posts on Twitter and legal problems, are misdemeanors. …