Neither, the Nahel Bond is between spren and Radiant, that isn't being shared. An Aviar can grant a temporary Bond, it seems, but still only to one person. Being a Regal has to do with Voidspren, who might not follow the same rules and being of the race of the Singers, so nope.
Squirehood is either a bond with the Radiant themselves to grant the ability to breath in Stormlight or just guidance to help the squire as a prospective Knight on the path to Radiancy. As we see, Stormlight can be drawn before even the First Ideal is sworn and one can even use their Surges before a spren initiates the Bond. We see these instances occurring in various degrees across the Orders of the Windrunners, Skybreakers and Lightweavers.