"hand-formed" in Japanese when referring to pottery or ceramics is "tebineri" (手握り). Therefore, the translation for "handmade bonsai pot formed by hand" using "tebineri" would be: "tezukuri de tate-namashita bonsai hachi" (手作りで手捏ねした盆栽鉢).  This phrase emphasizes that the bonsai pot was handcrafted using hand-forming techniques.