"Am rivals" can be interpreted as two individuals, teams or organizations who are in competition with each other. The antonym for this phrase would be "am allies". This implies that these two parties are supporting each other and working together for a common goal. Other antonyms could include "am friends", "am partners" or "am colleagues". These words indicate a friendly and cooperative relationship among people who share mutual respect and trust. In contrast, "am rivals" implies a sense of animosity, rivalry, and a competitive spirit. People who are rivals are focused on beating each other, rather than supporting each other.