I had very similar experience.
In 2014 applied for reception v place middle child.
Did not get eldest school as council won't give sibling link to those outside apr we live just over a mile.
Dident get any of 3 preferences including nearest infants.
Council said I could only be on waitlist v for r I could only bank 3 so accept one and on waitlist for 2.
I dident like allocated school was distance from home eldest school we knew no one and wasent great.
I turned it down knowing I was taking risk.
We do nursery school using free 15hours and home educated.
I honestly expected get something by xmas that went.
If course then had apply again youngest by jan 2014 and everywhere I put down has no sibling link.
Put similar preference to middle child only 2nd preference different hut long shot as in another county and we live I loan the border also school1 and school 3 sits on county border so kids other county got space as they nearer.
Council changed catchment area school 3 making it harder kids from.other county get in its 75 intake so this time youngest got 3rd pre fence nearest infants in april.
Council said nit until he starts does middle child get up to no 1 on waitlist and sibling link.
Just by chance she got offered reception year at infants 4weeks before school ended so did 4weeks reception and had a year 1 space.
We accepted local infants fir son but defered.
He's been offered reception space 2 half weeks into term as 1 child failed show up and another one left he was lucky as we lost both appeal s.
But middle child moved down to no 2 on waitlist as family new area moved closer.
No one has left her year loads have left year above.
its so frustrating ans nightmare doing 2 different schools and despite 2 at primary middle one has no sibling priority