Golf cart batteries are 220 - 240 AH so 2 will give you 220 - 240 AH @ 12 volts.
A 100 watt panel is rated at about 5.6 amps. With a good controller (MPPT) that can get an output of about 7 amps at charging voltage. On a sunny day without panel shading you can get about 35 AH into the batteries from such a panel.
If you are only getting 8 or 9 AH per day something is wrong.
you are correct on Ah ratings, phone is too small
I have 2 @225 Ah each, and the 8-9amps was purely a thrown out number for
possible worst case
Most people new to solar dont think about the variables that you removed
from the game
as for output, dont forget if you just throw it on a flat surface that does not get full sun angle, unless you are real close to the equator, output could be that low with clouds and shade in the mix,a shadow from a line/cable can reduce output also, then throw in a heated panel and possible small wiring and a heated battery
solar has so many variables when you go mobile with it, best thing is to read everything you can to help make desiesions your happy with
a friend listened to everyone and mounted a 50 wt panel flat on top of his black truck roof, in N.VA and used one 12v deep cycle battery, it would not run his fridge for more that a day-1/2
same setup angled towards sun in Cochise Co Az, kept fridge going all weekend, lots of variables
Great site by the way, thanks...just need to get a boat and learn to sail
measure boat surfaces before looking for panels, 100+ wt panels are pretty big