It's certainly questionable on two grounds. First, the nature of the business must be specified in the summons (of which the agenda may be deemed a part). Case law plainly indicates that this needs to be done in some detail, and if the council is to approve the payments, then it is certainly arguable that it is too vague without the explicit list.
Secondly, the publication scheme should ensure that the agenda and all supporting documents are made available in good time for both councillors and citizens. The list of payments is clearly an important supporting document.
It's not really hard to do these things right and make sure everybody is properly informed about what is going on! A good council welcomes citizen involvement.