Being able to mount it, says nothing about the correctness of the length of audio tracks for example or the amount of audio tracks. (which can be used as cd check)
It only means that DOSBox sees no errors which keep it from mounting (and accessing the data track).
Still it is possible that dosbox is bugged, but the cue/bin mounting is a very often used feature to replace real CDROMs. (and as we don't depend on the OS, it is far easier to implement all features in it, so it is the most feature complete of all types of CDRROMs that we emulate)
Anyway, with regards to your original question. Yes mounting a good cue/bin file will result in a CDROM emulation which works very well.
If it doesn't work for a specific case, then either the cue has wrong information or the bin has some problems or dosbox is bugged.
However, there are several image creation programs which produce wrong images for DOS games.
So maybe post your cue file and maybe somebody else has made a cue bin as well.