Hi TS
There are many similiarities between Reflex and TFM, but the big different is the approach of these therapies. In Reflex, there is an emphasis on working the reflex points of the feet in a precise way or combination to work with specific ailments, using thumb pressures. With TFM, the reflex points may just be pressed for general wellbeing, using a stick, thumb or knuckle pressures.
Also most reflexologists just work the feet and ankle areas, but TFM therapists massage the feet and lower leg up to the knee and may even use stretching techniques.
Both systems use a concept of energy lines, Reflex uses the principle of 10 longitudinal zones/lines, and TFM uses Sen lines which is more like Chinese meridian system. Actually the Thai Sen lines are very similar to as modern concept in bodywork known as myofascial meridians or anatomy trains, and is based on structural physiology, where as longitudinal zones/lines in Reflex is more of a mental construct.
From my experience of practising both systems, Reflex is a more sophisticated* pressure point healing art but uses mainly thumb walking techinque (which often causes RSI in therapists). TFM is more of a foot/lower leg massage but has more varied pressing techniques (less likelihood of getting RSI). Personally I like mixing the both and getting the best of both worlds - east and west.
Best wishes
RP
*What I mean by sophisticated is that for example in Reflexology, if somone had say asthma, you would work the lungs, adrenal, kidneys, ileo-caecal valve & large intestine, diaphramic, and solar plexus reflex points to help the the sufferer; but in TFM this type of knowledge or way of thinking isn't taught, just pressing and stroking.