Evidence Against Both Pairings
(From Fandom)

Yugi/Tea

• Not a lot of interaction/alone time in many of the aired arcs so far, excepting Duelist Kingdom and Doom Organization
• Yugi often seems closer to Yami than to any of the girls
• Tea's feelings for Yami could get in the way of her friendship with Yugi

Yami/Tea

• Tea doesn't have an Egyptian past, so she can't interface with him in the last season of the show
• Ishizu seems closer to Yami because she is older and has a Millennium Item
• Yami enters the afterlife and effectively dies before either of them can truly share their feelings with each other