Are you sure that you see 2 tiles because they are physically encoded as 2 images, or could it be that the emulator shows you tiles with a "default" size it chose (say 8*8 pixels) instead of what the program assumes (8*16 pixels)?
For finding text: it doesn't matter that it's on 2 vertical tiles. What matters is the order of the letters. So do as if there was one 8*16 pixels tile per letter, and you didn't have this problem.
Edit: More background on the logic behind this: When you see these kinds of things, always think about how you would go about coding a program that uses this piece of data. In this case, you'd probably still encode a letter with a number, and then do some calculations with the number to find the tiles to use.
About encryption: you cry, you suffer. There's no generic rule for all cases.
Edit: Going a bit further on this:
- you look for text as if it was not encrypted. If it works, you are happy and you run naked around your place shouting about how life is good. (or not)
- if you don't, find it, try again a couple of times with different approaches. I mean - don't give up right away because you used RSearch. Search for different words. Assume a couple of orders.
- if you don't find it, there are 2 approaches usually: either you try to see how the code behaves, or you try to interpret the data. Or a bit of both.
To see how code behaves, you need ASM understanding. You need to find where it displays text (or uses the textures you posted), and work backwards from there to see how it chose the tiles, and from there how it calculated numbers that allowed to choose tiles, etc.
To interpret the data, you need to find where it is (which is the tricky part) and then see if you understand how it is organized. This link could be useful, maybe: http://zenhax.com/viewtopic.php?f=4&t=27
Again: don't look for encryption where it is not. Assume luck, be persistent.
Good luck in your endeavors!