i don't know that much about treefrog species you want to mix with the others, so you may be on your own with that one. a 45 gal. tank should be fine for the 2 retf and 3 anoles, but if you decide to add others you may want to get a larger tank.

i had a 55 gal. tank with 2 green treefrogs, 1 squirrel treefrog, 1 golden treefrog (juvie), 4 female green anoles, 2 female brown anoles, 1 male brown anole, and 3 house geckos. it was a planted tank, with two exo-terra waterfalls, a mixed soil substrate, and UVA/UVB flourscent lights and a 50 watt flood heat light.