Initial paragraph is kind of copy pasting my reply to the question that got deleted, while I was typing it.
Yoga and yogi/yogini mean different things to different religions.
To hindus yoga is completion and a yogi/yogini is one who has mastered their respective religious arts.
To some Buddhists a yogi is a highly attained master of meditation (jhana) who is not ordained, a lay person.
To other people a yogi is just someone who practices yoga, to others it is a teacher of yoga.
You have to find and elaborate the definitions of the words.
In Tibetan Buddhism a yogi is a high level attainer, someone who has attained high levels of bliss and experience in emptiness. One can be ordained or not, though generally I have seen that only the high level ordained tantric masters are called yogis, normally they are titled rinpoche (teacher) rather than yogi, though they "are" yogis.
Then on the other side you have lay practitioners at varying levels of experience who are called yogis/yoginis.
Like for eg Marpa and Millareppa were called Yogis, neither of them were ordained but both of them are seen as Buddhas in Tibetan Buddhism.
Also Mahasiddhas like Tilopa and Naropa were called yogis.
In karma kaguya Tibetan Buddhism, which is an oral transmission of tantric practices, which are from the successive lineage from Tilopa,Naropa,Marpa and Milareppa, the practitioners in this sect are generally called Yogis, despite that they are ordained.
So generally the word, yoga and yogi is different from each religion to each sect.
I myself would explain it like this:
Firstly what is generally seen or called as yoga, the flexible posture exercises are only a part of yoga, they are called "yoga asana"
Yoga itself means completion and is a religion in of itself, parts of this is stuff like asana, pranayama (chi gong) and samadhi.
A yogi/yogini is a non ordained high level attainer with a refined mind. So high level of jhana, high experience in samadhi and/or sunyata. Not especially a teacher or a scholar, just someone who has put the "cushion hours" in and has practical experience and skill in the meditations.
One following the yogi path or path of yoga is one who is not looking to become an ordained disciple of the Buddha, or even specifically a Buddhist, just one who is determined to find the answers to lifes riddle within themselves.
So yes Yoga/yogi is used in at least Tibetan Buddhism, Vajrayana but i expect Mahayana as well. There are even Tantric practices called Yoga Tantra.
I have never read anything such as yoga or yogi in the pali cannon. As too are things like chakras, prana or shashamuras, the esoteric body functions not in the pali cannon.
Hindu and vajrayana word for yoga and yogi mean different things, but they do fall under a similar branch of common understanding with yoga meaning completion or path to completion and a yogi as a practitioner or high level attainer of yoga.