The successful bond sales in Taiwan, which is sitting on a pile of 123 billion of yuan deposits, have whetted mainland firms' appetite for more debt issuance on the island.
Analysts said the size of Formosa bonds could top 60 billion yuan in two to three years as the mainland and Taiwan consolidated their economic ties.
Yuan deposits now account for 17 percent of overall foreign currency deposits, up from 6 percent in February when Taiwan allowed domestic banking units to conduct yuan business, Phoo said.
In Taiwan, the central bank limits the conversion to 20,000 yuan per person per day.
Bocom's three-year notes worth 800 million yuan carry an interest rate of 3.4 per cent while its 400 million yuan five-year bonds were offered at an interest rate of 3.7 per cent, far lower than borrowing rates on the mainland.
A yuan debt craze in Taiwan, however, would not be a threat to Hong Kong's role as the dominant offshore yuan market. Hong Kong's yuan deposits still have a wider access to the mainland market and assets.
Apart from dim sum bonds, yuan assets in Hong Kong can be ploughed into the renminbi qualified foreign institutional investor scheme to invest in mainland equities and bonds.