A relatively obscure ICANN rule applies to the transfer of recently renewed domains. In short, if you transfer a domain that has been renewed within the previous 45 days, then you will lose credit for the renewal. This will appear to mean that you did not receive the extra year added upon the successful transfer of your domain.
Where can I read more about this rule?
Although the article is relatively old and contains out-dated pricing information (it was published in 2002), you can read more about this rule from ICANN's Registrar Advisory Concerning Registration Transfers Within the Auto-Renew Grace Period. In particular, please pay attention to this section:
If a domain is transferred under Part A of Exhibit B to the Registry-Registrar Agreement within the Auto-Renew Grace Period, the losing Registrar is credited with the Auto-Renew charge* and the year added by the Auto-Renew operation is cancelled. The expiration date of the domain is extended by one year up to a total maximum of ten by virtue of the transfer and the gaining Registrar is charged for that additional year, even in cases where a full year is not added because of the 10-year maximum limitation.
In short, this means that transfers occurring during the 45-day Auto-Renew Grace Period result in the losing registrar being refunded for the cost of the renewal.
So, did I get the extra year added to my domain?
The short answer is yes, you did. Here is what happened chronologically:
Your domain expired while with your old registrar (the losing registrar)
You placed a renewal order with the losing registrar and the applicable time was added to the expiration of the domain, and the losing registrar was chraged by the registry.
You transferred the domain to mnchost.
The transfer completed.
The losing registrar is refunded the renewal fee by the registry, and the year(s) added from the renewal in Step 2 were deducted.
mnchost is charged for the transfer by the registry and one year is added to the expiration date as though the renewal in Step 2 never took place.