I had this happen around my gas cap after a repaint. I was told it IS caused by a small hole, and when the tank gets hot, the fumes expand and push out the hole, and up into the paint.
It looks like crap..I say POP it and push it back down and hope it doesn't look bad. I don't think the holes are big enough for any signifigant ammount of gas to leak out...if any. But I could be wrong.
I'll have to keep an eye on it. I punctured it with a scribe and tried to flatten it, but the paint is stretched into the bubble shape now. The tank is full, and I can't smell any gas odor, even after "milking" the bubble and sniffing for fumes.
I'll probably end up looking under the paint and then fixing it just to see what it is.
Sounds like a leak to me too, but it seems like an odd place for a leak & you would smell gas for sure if it was. Pop it & start looking. If it is any kind of leak, you can fix it easily with POR-15. They sell a kit specifically for motorcycle tanks.
I think you should remove the tank and inspect it very carefully for rust. What you have doesn't exactly sound like rust, but better safe than sorry. Seems like finish defaults would show up way before nine years, and rust takes time. Anyway, with the tank off it will be easier to take it to someone to check it out.
It's weird - still. Inside of tank looks pretty clean, fuel filter has never shown any rust particles. I sliced into the bubbles and found it's all between the primer and surface coat. The upper half of the primer is damaged a little by whatever caused the bubbles, but the bottom of the primer coat and the metal underneath is clean and sound.