No, not just Vajrayana, but all sects and schools of Mahayana Buddhism teach the Trikaya doctrine.
The doctrine of the three bodies of a Buddha is ultimately for the purpose of teaching that all beings, including you and I, have the potential to become buddhas.
If the Trikaya doctrine is true, then your body is the body of a buddha (at least potentially), through Buddhist practice.
The seeds of the Trikaya doctrine are found in the Pali canon:
Even before the Buddha’s parinirvāṇa, the term Dhammakāya was current. Dhammakāya literally means Truth body.
In the Pāli Canon, Gautama Buddha tells Vasettha that the Tathāgata (the Buddha) is the Dhammakāya, the ‘Truth-body’ or the ‘Embodiment of Truth’, as well as Dhammabhūta, ‘Truth-become’, ‘One who has become Truth’ 
The Buddha is equated with the Dhamma: “[T]he Buddha comforts him, ‘Enough, Vakkali. Why do you want to see this filthy body? Whoever sees the Dhamma sees me; whoever sees me sees the Dhamma.’”
In the Aggañña Sutta, the Buddha advises Vasettha that whoever has strong, deep rooted, and established belief in the Tathagatha, he can declare that he is the child of Bhagavan, born from the mouth of Dhamma, created from Dhamma, and the heir of Dhamma. Because the titles of the Tathagatha are: The Body of Dhamma, The Body of Brahma, the Manifestation of Dhamma, and the Manifestation of Brahma.