The Bears batted first in the final with Wong again top-scoring for her side with 31 before being bowled by Alexa Stonehouse.
Laura Harris, the sister of Surrey’s Grace, struck a typically ferocious 25 from 11 but the Bears struggled to build partnerships.
Phoebe Franklin was the pick of the Surrey attack with 2-16, while two run outs helped to further restrict the Bears to 153-9 in 20 overs.
Surrey suffered early blows in their reply when Danni Wyatt-Hodge holed out to Em Arlott in the deep and Bryony Smith fell to the last ball in the powerplay.
They were further rocked when Nat Wraith stumped Alice Capsey off Hannah Baker to leave them 42-3.
Sophia Dunkley got Surrey back on course with three boundaries from Millie Taylor’s opening over and a six off Baker in the next.
When Dunkley was out to a smart piece of work behind the stumps from Wraith, Grace Harris took up the baton to play the match-defining innings, charging to her half-century at a strike rate of 200 and seeing her side home to claim the trophy.