So the hotel has not reported correctly? That should not be your problem, but ends up being so when you have to apply for an extension...
Had problems getting the TM-30 in twice now, visiting my girlfriend and staying at their plac(es). In the end I had to take what papers we had alongside with a note from her to immigration, and get the receipt myself - no real problem, and I could have gotten an extension the same day.
Seems like they are OK as long as some TM-30 is delivered at some point before extending, they are well aware of how complicated it can be for ordinary thais to get this in on behalf of their visitors...
Just did the TM30, lots of hassle to get it in - second time I´m staying with my girfriend here at various locations.
It will quite likely work just fine staying in private homes without sending it in, but also seems that some actually get fined the 1600 baht for not reporting...
I prefer to have a clean track record if possible, it should actually be sent inside of 24 hours when staying in private homes - but getting it in can be complicated if the owner does not have the deed for the property etc, etc...