It *may* be bongso, but Charles has not listed bongso as a species with which inermis hybridises in the wild. As the plant is not mature, it is impossible to tell. The uppers should give a very good indication of whether it is a hybrid, and if so what and to what extent. There are other red species with which it could have hybridised if it is indeed a hybrid. If it were 1/2 bongso, then it would show much less reduced inermis traits and very pronounced bongso ones. As it is, the inermis features are the most obvious by far, the differing traits are overall fairly minor, but enough to give a sneaking suspicion that it is not pure species, certainly Charles has his doubts. To give a definite answer without seeing the plant is a bit didactive.
Anyway, once it is bigger Charles will be able to give his expert opinion.
As for reliability of the supplier, we could argue that one, but it's a debate I'll have off-line as it's very political. As I can say with any TC material that is from wild-collected seed, the purity can never be reliable. All one is ever certain of is the female parentage. Most suppliers release TC material as soon as it is ready, they generally don't grow the full line of clones to flowering maturity before releasing them commercially. Ditto with a lot of the seed grown material of new species being released now - there might be a few surprises there, as there have been in the past.
So the waiting game continues.