Are all those juristictions in communion with each other?
Those are just the TOC synods that have a presence in America. In America, the only synods that are in communion with each other are the Synod in Resistance under Met. Cyprian of Fili and ROCOR under Met. Agafangel of Odessa. There are other synods who are not listed on that site as they don't have a presence in America. For example, the synod I am a member of is in communion with a Russian Catacomb synod, a Greek synod, and a Bulgarian synod, as you can see here if you look on the left portion of the website:http://www.hermitage-journal.org/
I know that HOCNA has officially stated (although I can't find it at the moment) that they'll allow laymen of other TOC synods not in communion with HOCNA to partake of the Sacraments in HOCNA as long as HOCNA recognizes their bishop as being a TOC bishop, and as long as the laymen's bishop recognizes HOCNAs Met. Ephraim as being a TOC bishop. While I do not have much experience with synods other than my own, from what I have read, I would imagine that there are other synods who would follow this HOCNA example, just as their are synods that are more safeguarding of the Sacraments and will only allow people who are in communion with them to partake in their Sacraments.