My bet is that no one at JET2 knows what packages are on offer, as the variables are too many and no decision has yet been taken, as they don't know what experience is available in the job market and exactly how they propose to target the recruitment.
See my earlier post on last year's recruitment drive for experienced type rated pilots and the package offered and work backwards or forwards according to your experience/abilities etc.
The telephone interview was partly to decide whether you were a likely candidate for employment, so that any money spent on you on a further interview, would not necessarily be wasted.