Yes.
It definitely does matter. As much as we would all like it not to, it does matter.
Sure, the licence you get at the end is exactly the same but it's getting the first job that is the hard bit. If the school you choose has known connections with an airline then there is a greater chance of being recommended if they come looking for new pilots.
If the school you choose does not have connections then you are entering into the lottery with everyone else.
When it comes to second and third airline jobs then no, it doesn't matter any longer.