Praise be to Allah.
There is no sin on you for passing the meeqaat without entering ihraam, because you were not intending to do Hajj or ‘Umrah at that time, and you were intending to enter ihraam on the eighth day from your home. This may be understood from the words of the Prophet (peace and blessings of Allaah be upon him) concerning the meeqaats: “And these meeqaats are for the people at those very places, and besides them for those who come thorough those places with the intention of performing Hajj and 'Umrah; and whoever is living within these boundaries can enter Ihram from the place he starts, and the people of Makkah can start from Makkah.” Narrated by al-Bukhaari (1524) and Muslim (1181).
The same applies if a Makkan goes out to al-Taa’if or Jeddah, then he comes back and is not intending to do Hajj or ‘Umrah. He does not have to enter ihraam, according to the more correct of the two scholarly opinions.
It says in Fataawa al-Lajnah al-Daa’imah (11/122): The one who passes by any of the meeqaats which are proven from the Messenger of Allaah (peace and blessings of Allaah be upon him) or comes in line with them by air, land or sea, and he intends to perform Hajj or ‘Umrah, then he must enter ihraam, but if he does not intend to perform Hajj or ‘Umrah, then he does not have to enter ihraam. End quote.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked: If a Makkan goes out to Jeddah, for example, then he comes back to Makkah on the fifth day of Dhu’l-Hijjah, and he intends to do Hajj this year, does he have to enter ihraam from Jeddah? Can he enter ihraam for ‘Umrah and do Hajj tamattu’?
He replied: He can enter ihraam for ‘Umrah and do tamattu’. If he intends to do Hajj, he does not have to enter ihraam from Jeddah, because his family are in Makkah. End quote from Fataawa al-Shaykh Ibn ‘Uthaymeen (21/326).
The words “because his family are in Makkah” mean that he is one of the people of Makkah who reside there. The fact that your wife went out with you to al-Taa’if does not make a difference; the ruling is still the same.
And Allaah knows best.