in rare circumstances,people will be bailed whilst awaiting appeal,if you win your appeal,you are set free,if the sentence is reduced on appeal and you have done enough time in prison,then you are free.
if you have been given a custodial for a summary offence i would suggest that this is not your first offence of this type / nature.
the question of bail whislt the appeal is being heard depends on many circumstances not least the arguement you legal representative puts forward. your criminal past will also have a baring on the matter.
if the appeal is allowed and it is found that the orginal tariff was not proportionate with the offence there could be an avenue open to you to claim some form of compensation. your legal representative would be able to advise you on the likelihood of this. but i would'nt hold your breath.