iMessage "delivered" I sent my friend an iMessage about 4 hours ago, and the blue bubble appeared, but delivered text never appeared below the message bubble. I assume this means that the recipient did not receive the message.
I just sent them another iMessage and this time it said delivered.

Does that mean that my friend was able to receive both the messages or just the most recent one? And is the first message lost in transit?
Your friend was able to receive both the messages.

The former message was not lost in transit.