Sadly, there is no longer a bus from FW to the TTC. From the TTC, there is a Lynx bus (56) that goes to the Wal*Mart for only $1.50 per person.
Personally, though... unless you need some Wal*Mart only items, I'd recommend shopping at the Publix by Gaylord Palms, or the Winn-Dixie on 535, near the Ale House. Both are much closer, and will save you a lot on a taxi. They also have decent prices.