I think that you had better rewrite this letter because it sound quite bad. If you are writing to your boss, I think he will feel little disappointed.
As I was trained in my college, you should begin with " Dear sir...."
Then " I am writing to you to inform...." (informal) or " I write to you to .." (formal).
I think " personal" is unnecessary.
" and for company purpose" should be " because of useful company's purpose"
You must use a dot before "therefore"
" Therefore, I wonder whether you would mind providing him with a communication allowance"
I hope my knowledge may help u!