"Can you explain how meditation and Taiji work together as one? Not an easy task, no doubt... Coming from a Buddhist perspective!?"
Many Chinese martial arts (including Tai Chi) were influenced by the Shaolin monks' training, which was taught to them by Indian Buddhist monk - Bodhidharma. He was disturbed by the monks poor physical health, and showed them "tendon changing" exercises (Yi Jin Jing), which were later adapted into the self-defence forms and skills we recognise today as Shaolin Chuan (Shaolin Boxing).
Bodhidharma was responsible for introducing meditation techniques to the Shaolin and he is associated with the idea that spiritual, intellectual and physical excellence are an indivisible whole necessary for enlightenment. It is this ethos that has cascaded through to many of the modern Chinese martial arts today - including Taijiquan.
To delve a little deeper and understand Tai Chi as a meditation, we have to understand the concepts of Wuji and Taiji (Tai Chi).
Wuji is the fundamental principle of stillness. It is a quality that is - in essence - empty and non-polar.
Taiji is extreme opposites (or supremely polar) and represents the interplay between yin and yang. (incidentally, it is this concept that was mis-translated for many generations as "the Grand Ultimate", which fuelled the fires of mysticism and bad teaching that is being corrected by better modern understanding). It is dynamic and polar, and represents the substantial and yielding qualities that are required for self defence.
Now - to attain Taiji (dynamic, polar) gongfu (skill), you must first attain wuji (stillness and emptiness). Meditation is merely focused consciousness. When practicing Tai Chi, the consciousness, movement and breathing are co-ordinated and can be interpreted as a holistic meditation. There are also meditative postures like Zhan Zhuang.
For further reading on Tai Chi and consciousness, try here: