Yonfan first met T’ang Haywen in the 1980s through their mutual acquaintance, Madame Song. In the Spring of 1991, Yonfan published a photography album titled A Chinese Portrait in Hong Kong, featuring T’ang alongside other prominent Chinese figures abroad, including the painters Zao Wou-Ki (1920-2013) and Chang Dai-Chien (1899-1983), as well as the architect I.M. Pei (1917-2019).

The last known photo-portrait of T’ang was taken by Yonfan in the Spring of 1991 on rue Liancourt in Paris. This poignant image captures T’ang during a period when Yonfan was planning to exhibit his work in Hong Kong. However, T’ang’s passing in September 1991 prevented the project from coming to fruition.

In 1997, Yonfan made a significant donation of Chinese paintings to the Guimet Museum of Asian Arts in Paris. This included the first Song Dynasty (11th–12th century) painting to enter the collection of the French State, as well as Chang Dai-Chien’s The Lady of the Xiang River, which he donated as a tribute to Princess Diana, who had recently passed away in a tragic accident.

In 1998, as a personal homage to T’ang Haywen, Yonfan donated 12 small portraits painted by T’ang in the late 1980s to the Guimet Museum in Paris.

In September 2017, Yonfan served as a member of the jury at the prestigious Venice Film Festival, further solidifying his influence in the global film industry.