I'm an Arabic young guy, married Muslim, but I study in Australia without my family. I tried much to bring them but the visa is taking much time. Anyway, I love my wife, so much. I can't stop thinking of her psychologically and sexually, and the matter is same with her. So, are we allowed to practise "phone sex" to release our passion till we're meet.

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

We advise a husband not to talk about the sexual matters with his wife on phone. The appropriate place for such talk is being alone with her in a place no one can be aware of it. Phone is an insecure means of communication. It is very easy to listen or even tape a conversation made on phone. Therefore, it is better to avoid discussing such matters on phone.
Some scholars explain the verse: "… They are Libas [i.e. body cover, or screen, or Sakan, (i.e. you enjoy the pleasure of living with her - as in Verse 7:189) Tafsir At-Tabari], for you and you are the same for them. …"[2:187] that it means totally covering each other.
Imam Qurtubi said: 'The expression of Libas (garment) in the above verse means that a husband and wife cover each other and mix with each other just as a garment does. Also they hide the sexual matters which take place between them as a garment hides nakedness of human bodies'.
To cover such matters, one should avoid talking about sex on phone perhaps accidentally one may come to know about it.
If you mean by "Phone sex" that the conversation with your wife causes you to ejaculate then there is no harm in it. Because the reason of ejaculation in this case, is talking with one's wife which is permissible.
If you mean that you masturbate while talking with her using hand or any means, then it is forbidden. For more details, please read the Fatwa: 81167.
Allah knows best.