I cannot find out what exactly the proposed area should include. The Sea of Galilee, regardless of its Chritsian holy status, is indeed surrounded by numerous ancient sites. Their intergrity is questionable though, mainly due to the fact that some of the territory (the Golan hights) is internationally considered as an occupied Syrian territory. On the Israeli (internationally recognised) side several sites (Capernaum, Hurvat Minnim, Hammat Tiberias) are already proposed under other titles (ancient synagogues, Christian pilgrim routes and Hurvat Minnim respectively).
Tiberias is now a modern town, its historic Mamluk-Ottoman centre having been almost completely demolished by the Israeli army during the 50s. Whatever is left of it is far from impressive and lacks integrity. New excavation of Roman Tiberias are underway at what is now called Barko Park. There is not much to see there yet. Nearby Hamat Tiberias offers a nice synagogue mosaic, but it is not mentioned in the description.
Capernaum is a popular pilgrim site and boasts a magnificent marble synagogue as well as the remains of a Roman settlement. Tabgha features two churches with archaeological findings - the mosaic of the Bread and Fish is the better known of the two. There is now a scenic walk along the shore connecting Tiberias and Capernaum passing through Tabgha and Hurvat Minnim.
As you can probably sense reading my review, I cannot really grasp the unifying element that would justify a common inscription of the sites, but maybe a more detailed description would shed some light on how this could be argued. Notwithstanding, the fact that the lake is a source of a political conflict could probably suffice to exclude the site.