Hi! For what it's worth, I vote WG Single Row. I think that Single Row between the Clover and Thin Clover will add a nice touch of bling. The two bangles now have a lot of metal, so I think the Single Row between might be a great look.
The downside to the Single Row might me too much milgrain beading. It may be too many "bead rows" and start looking like a bunch of bead bangles as now you have 6 rows of beads. You can see if it takes away from the clovers and diamond accents as the Clover bangle can look like a lot of metal (unless the metal bangle look is what you want... e.g. stacked with Love). I think it will look fine though. Plan B is the three row bangle to give it more diamond bling effect, depending on the look you're going for.
I vote another VCA bangle though... Single Row or Three Row as I think those are prefect matches for your Perlees. The Serpenti has bezeled edges vs. beaded edges, and I see it as a bit more contemporary looking vs. the beaded milgrain which is more classic/old-world. I think the Serpenti would look great with the Lotus Ring, and I thought you have the Lotus Ring too.
Just my two cents on thoughts here. I hope this helps with your decision! Of course it's all preference, and all VCA is gorgeous and you have some very beautiful pieces to play around with!