In the Philippines, senior citizens are entitled to a 20% discount on domestic flights under the Expanded Senior Citizens Act (RA 9994). Usually, they can also book a companion ticket for an accompanying person, but this depends on the airline's specific policies. Some airlines may require the companion to be a senior themselves, while others do not. It's best to check directly with the airline for their specific rules and procedures regarding companion tickets for senior citizens. For the most accurate information, visit the airline's official website or contact their customer service.