There have been a number of questions raised in the UK and abroad about the relationship between TMMi and the new ISO 29119 standard.
To clarify the situation, the TMMi Foundation has been very active in addressing the questions by pulling together a group of 25 volunteers who conducted an in-depth review of the differences and areas of overlap.
This has resulted in an excellent paper being written and published by Erik van Veenendaal. The paper highlights and describes the main conclusions and some findings from the study.
Rather than summarise the paper here, I would strongly recommend you download it from this link and have a read so you get to know all there is to know about the link between TMMi and ISO 29119.