That was released 20 years ago (1990), the licensing situation for Tetris has changed a lot since then. There's actually a specific set of guidelines The Tetris Company enforces for a game to carry the Tetris name. They dictate everything from the piece colors to the playfield size:

http://tetris.wikia.com/wiki/Tetris_Guideline

Aside from that, if they were using it under license, there would be a licensing blurb, similar to what you see in the footer of tetris.com.