The San Francisco Peace Treaty did not mention the beneficiary of Taiwan. It is because there is a controversy on the recipient of sovereignty -- the UK-recognized Communist in Beijing, or the US-recognized Kuomintang in Taipei at the moment. However, since the PRC was established, it has not exercised any control over Taiwan. The people of Taiwan are the only ones who have the right to claim sovereignty over Taiwan. The Treaty, therefore, provides the people of Taiwan with the legal basis for their right to self-determination.
Article 1(2) of the Charter of the United Nations states: The purposes of the United Nations are: "To develop friendly relations among nations based on respect for the principle of equal rights and self-determination of peoples….." It provides the people of Taiwan with the legal basis for their right of self-determination. Their quest for self-determination is guaranteed by international treaties such as the UN Charter.