It was politically incorrect during the culture revolution period for Taiji symbol used in the coin/medal design, but not post-1990. Here is an example of Taiji symbol was used in one of the coin in 1993 I & D set.
Yes,you are right,Taiji symbol used in the coin design in 1993 China ancient Chinese science and technology invention coins.
The reason why I think this medal was minted by China Taiwan or China Hongkong mint(I am sorry I missed the Hongkong mint in the previous reply).
When a coin is designed,it will be related to various factors such as local culture,in fact, as I said before,Promotion of Tai Chi Bagua in China is far below in Taiwan and Hongkong area.In Taiwan and Hongkong area, most of the people believe in Feng Shui, believe that Tai Chi Bagua,but in China only a very small part of people believe in it.People in Taiwan and Hong Kong area career in this part of the legal, and can get people's respect,but in the China it is really hard.Back up to the medal itself.The whole side of the design with the map of Taiji Bagua and Related words.this way of design will be popular by people in Taiwan and Hong Kong area.but not necessarily be welcome in China.(Such as that 1993 China ancient Chinese science and technology invention coins,most of the design is the figure,only a little for the map of Taiji Bagua).If the consumer group is defined as the native people,this way of design will not be used by China mint,but the Taiwan and Hongkong mint will use.Or I can say, the design of this medal will be more popular by the people in Taiwan and Hongkong area than in China.that is why I think it was minted by Taiwan or Hongkong mint ,not by China mint.In addition,the design of the dog,this kind of dog is unfamiliar in China in 1994,and this kind of dog is not the dog in traditional idea of the chinese.so I think a more familiar kinds of dog will be used by China mint if it is minted by China mint.
By the way,it is just only my personal opinion