It is claimed that the Qur'aanic verse: "Let there be a group amongst you who will call to good….." refers exclusively to the Tabligh Jamaat.

Answer

The Qur'aanic aayat cited by you applies to any sincere group of Muslims who calls towards the Deen and prohibits evil. Whilst the Tabligh Jamaat also comes within the scope of the aayat, this aayat does not exclusively refer to the Tabligh Jamaat. If you offer Deeni advice to others, then you too will come within the scope of the aayat. Every group of individuals engaging in Deeni activity in which Amr Bil Ma'roof Nahy Anil Munkar (Commanding righteousness and prohibiting evil) is the objective, comes within the scope of the aayat.

It is not compulsory to participate in Tabligh Jamaat activities. Your wife can acquire the basic quota of Islamic knowledge necessary for her daily acts of Ibaadat, etc., from reliable Islamic books which she should study within the confines of her home. There is no need for women to participate in Tabligh Jamaat activities. Furthermore, it is not permissible for women to travel from town to town and country to country on Tabligh missions.