I tried both "junglebiome123" and "junglebiometest123". 123 spawned me into a world with a cliff overlooking a lake, and test123 into a snowy forest (lol, the exact opposite of a jungle).
I think I'm just gonna go hunt for a jungle in my own world
Seeds seem to be random.. same seeds work for some people but not for others, I simply tried the seed "Jungle" and it spawned me right into atop a Jungle tree, yet neither of these seeds spawned me within sight of one
trust me, try out "CrimsonDarkness" as a seed, easily the best jungle seed ive ever played on. its entirely unique. but i wont ruin the suprises for you and yes there are several surface dungeons on that map