When using bone meal on moss blocks, they are supposed to turn the adjacent blocks into moss blocks, however if the block has a torch, chain block, iron bar, fence, or any other block on top of them, the moss does not spread.
- Place a moss block with stone next to it, with a torch on top of the stone
- Apply bone meal to the moss block
The moss does not spread to the stone
The moss would spread to the stone regardless of whether or not a block is present above the stone.