Hmm, I personally think the Viera are matriarchal in their society - but males do not conform to society, they are separate. However, the matriarchal part might actually come from the fact the spirit they worship and follow is female. The spirit they follow/worship also talks to them and communicates with them. Every Viera can do this barring those who 'leave' the wood who end up deaf to the wood. Anyway, the males talk to, protect and worship this female spirit. Not the Matriarch. The female spirit also sees them all as equal. Why the spirit wishes the males to be separate from the females - we do not know. But she does and if we're lucky we might find out. We do know that Viera were, not like this before, this way of life was a form of adaption after they lost their true homes millennia ago.
While with the Vii, they have a female chieftain, yes - but they followed the orders of a male Emperor. So this is not entirely matriarchal.
I wonder if the Viera in the wood has something that is akin to the 'Echo' in regards to this. Seeing as the Vii in the first were chosen to protect and bodyguard ancient texts and stories of the 'truth' of Zodiark and Mama Crystal. What if the Viera on the source are the same, but with most having the echo to talk to the manifestation of the wood. Remember that 'Vii' do not have this, the wood does not speak to them. Nor is there anything that hints the dulling of their hearing to understand the words of the wood when they leave it. Nor was there anything that hinted that the Vii had the same type of powers that the Viera had where they could hear and talk through the void itself/through the different fragments of the source and thus made amazing summoners due to this - I'm interested to see if this is true in FF14 as it is in the previous games and if Square will use this.
Can't forget that those who leave the wood - in the source - aren't called Viera anymore due to them turning back on the spirit of the wood and that lifestyle. Which can be argued, physically dulls them to the point their hearing can't hear/understand the wood anymore. It makes me wonder how that works. Why does being in the wood have them be able to understand or hear while leaving it has them going 'deaf' to it.
As I do recall in Golmore jungle - as we already know by the 24man - there is a huge abundance of crystals. It also houses ultima who is trying to replicate/copy the mother crystal - right down to her pose where she stands in the crystals when comes to images of a humanoid mama crystal in the old artworks of FF online.