They are made in different areas, and I believe, made with different raw materials and different production methods. However, they are fairly similar; people with a lot of experience can probably usually tell them apart, though I've heard that, while liu'an had a gap in production, liubao in liu'an size baskets was sometimes sold as liu'an. Both can have some medicinal / herbal tastes, and both are said to aid in digestion and help with constipation. From what I can gather, liu'an basket tea may be considered "cooling" [information based on article mentioned below], however, whereas liubao may be "warming" [numerous internet sources, but nothing super reliable].
The liu'an that I've experienced is usually in a 500g basket. Liubao baskets are often, but not always, much, much larger (up to 20 kilos for a single basket). Liubao is also more recently sometimes pressed into cakes which resemble pu'er cakes.
According to the article described here
in issue 5 of Art of Tea [pp10-15], liu'an has two production techniques. Both start with kill-green, like green tea or pu'er. For the first method (I guess you would say more like sheng pu'er), the tea is put into bamboo leaves and then baskets, and roasted in the basket to dry them. For the second method, the tea leaves are withered in the sun, kill-greened, and then rested for about half a year. Then, water is added, and the tea is wrapped / packed in the bamboo leaves and basket. The tea "ferments" like this, and then the baskets are dried.
The article also says that the tea is made in Qimen (祁门) in the south part of Anhui；same Qimen as Qimen (Keemun) red tea), but doesn't have a conclusive explanation as to why it's not produced in Liu'an (六安), which is in the west. My understanding from the article is that it likely does not use the same type of tea leaf as liuan guapian, and that further, that liu'an basket tea has been produced for a longer time than liuan guapian.
The inside is bamboo leaf, not bamboo bark (of the sort used for pu'er tongs). It's customary to brew a small piece of the bamboo leaf along with the tea. In my experience, the "raw" variety can be pretty bitter when young.
There is also liuan guapian, which is a famous green tea, also from Anhui.
Liubao is made in Guangxi. I don't know much about the manufacturing process; I believe it is similar in a lot of ways to liu'an. I don't know how accurate this description is, but this article
claims that liubao is partially oxidized after
kill-green. I can believe that it's partly oxidized, but not sure whether bruising will work after kill-green.