I'm not sure that the idea of expecting the Tour Manager to allocate tips for hotel staff would work. I've been on 6 JY holidays (I know others have been on many more) and on two of those the TM made it clear right at the start that he/she would have nothing to do with collection envelopes (though they were happy to receive those containing their tips).
On all my trips (except to Canada) there has been an envelope collection for the TM, with some people choosing to give separately, the coach driver has been tipped directly at the end of the stay, and all the hotels have provided either a basket, box or envelopes in which we could place our tips for the staff, with the assurance that anything we gave would be equally shared between all the staff. In all cases I have been confident that the hotel management would honour its pledge. Most people I have discussed it with have, like me, left something for the room maids on the bedside table on departure. In Canada I think everyone tipped the TM individually, with a note of thanks, because he had gone out of his way to make the holiday special. Not everyone who goes on a JY holiday is well-off and some may prefer the anonymity provided by a communal envelope.