There is one answer that satisfies the title, and all of the lines below.
I can bow to the enemy.
I am the opposite of myself.
I can help you, if you want to go back.
I am known for staying in a group of my kind.
What am I?
The answer is possibly...
The letter U
I can bow to the enemy: U = Yew, commonly used to make bows.
I am the opposite of myself: U = You, the opposite of "myself"
I can help you, if you want to go back: U-Turn.
I am known for staying in a group of my kind: U = Ewe, who usually group together in herds.
The title: the letter U is between T and V in the English alphabet.
I know there is an accepted answer, but this came to mind:
Beam
I can bow to the enemy: The beam in a television tube is bent magnetically to change the position on the opposing screen that it is shot at
I am the opposite of myself: A beam is something you send, but also something received
- - It is also something tangible (a wooden support beam) and something intangible (sunbeam)
I can help you, if you want to go back: "Beam me up, Scotty"
I am known for staying in a group of my kind: A laser beam is all one frequency of light, all going in the same direction.
The title: as mentioned it is used in tube TV technology.