Is there a special meaning to the 5 dragon lineages?

Yes.

虺五百年为蛟，蛟千年为龙，龙五百年为角龙，千年为应龙——《山海经》。

Also:

黄龙者，四龙之长，四方之正色，神灵之精也。能巨细，能幽明，能短能长，乍存乍亡。——《瑞应图》

In addition:

龙有五种颜色：白、青、黑、紅、黃。

对应五种方位：西、東、北、南、中。

对应五行：金、木、水、火、土。

对应五音：商、角、羽、徵、宫。

对应五脏：肺、肝、腎、心、脾。

(Source)

As you can see, there's a lot of meaning to having 5 dragons.