Well, if we're all here talking about pokemon in a positive light, we probably don't think it's "gay," do we?
The fact of the matter is is that all of the psychic pokemon in the original 150 were incredibly powered over any pokemon, especially a wimp like Tangela. Besides:

Grass and psychic have no relation whatsoever. You're thinking of pure bug types, who have strength against psychic types.
And no, Tangela does not learn any bug-type moves:
quote:
-
Constrict
Normal
-
Bind
Normal
29
Absorb
Grass
32
Poisonpowder
Poison
36
Stun Spore
Grass
39
Sleep Powder
Grass
45
Slam
Normal
49
Growth
Normal
So there.