From what I've seen it's very obvious that Kal'Reegar might have feelings for Tali beyond mere friendship. However, I sincerely doubt that Tali feel the same way about Reegar. She cares alot for Reegar, 'tis true, but she hasn't shown any signs of romance towards the poor bloke.
I smell a bad case of the friendzone!!!
And we must not forget that our beloved Tali is still a young lady with some daddy issues, something which might explain why she seem to have a thing for larger-than-life men. Her father was a huge, respected figure in the migrant fleet, while SHepard is a huge, respected figure in the alliance. Both were brilliant, tactical leaders in their own right, a trait which Tali herself seem to both idolize and (maybe) strives to emulate.
Though Garrus may not be as respected and clean-cut as Shepard, he is quite the character himself. A rugged, sharp-shooting, tactical genious with a strict sense of justice. He might not be as gentle and well-spoken as a paragon Shepard, and he and Tali have locked horns in childish bickering earlier. However that might be part of the appeal.
Though he is extremely different from what Tali sees as a perfect mate, he does have the qualities that she admires. Also, their differences and quarrels might be what makes him so attractive in the eyes of Tali.
He is so edgy, dangerous, frustrating, troublesome, annoying, yet so....Exciting

!!!!
Kal'Reegar is a marvelous, courageous individual, but measured up against these odds he just becomes a very nice soldier.