Spiritbonding Affected by Group Size?

[Ashkendor]

as far as I remember, SB gain is divided in the party, either it is formed with other players or your chocobo.

I can't see this being the case, or those 8 person parties in Urth's Gift would actually be pretty dang slow.

I've never noticed a difference in sb'ing with my choco out or in a party with 1-2 other players.

[Defteros]

I can't see this being the case, or those 8 person parties in Urth's Gift would actually be pretty dang slow.

I've never noticed a difference in sb'ing with my choco out or in a party with 1-2 other players.

probably, but I'm just assuming here, it might be because you kill more enemies in less time...
I'm always SBonding by myself, so I don't have proofs, but have you tried like, killing 1 set of mobs by yourself, and one with your choco out, or in a party?

[StouterTaru]

I can't see this being the case, or those 8 person parties in Urth's Gift would actually be pretty dang slow.

I've never noticed a difference in sb'ing with my choco out or in a party with 1-2 other players.

It is very noticeable solo vs solo +choco. Fight same level mobs, count kills, and measure at least 20% gain. It doesn't cut in half for two people, but it does reduce it.