Looks like it was short lived. They only held the belts for a week and lost them at the ROH Liverpool show on 3/3/07 (report from Stephen Lyon of wrestling observer):
6) In a huge surprise, Naruki Doi & Shingo (of Dragon Gate) won the ROH Tag Team titles, defeating Mark & Jay Briscoe in the match of the night. Awesome match. Doi & Shingo may have won the titles, but the Briscoes are the best tag team in the world today in my eyes. The Dragon Gate guys, especially Shingo (tremendous facials) were hugely impressive. Big crowd pop when Shingo pinned Jay. ****1/4.