I have made zero "mondy" as a sideman.
Seriously though, being a 'touring musician', or sideman isn't going to make anybody rich! Song publishing, merchandise sales, etc. generally aren't a part of the compensation for a hired gun.
Only the top-tier guys (either legendary sidemen like Steve Gadd, Steve Jordan, Pino Pallidino, etc...) or folks who land a gig touring with a top-tier arena gig (Dave Matthews Band type success) are going to get whopping 6-figure salaries and retainers.
Most of us (check my website for a selected resume) working 'in-the-trenches' live either check-to-check or count on a few very lucrative tours a year to make the bulk of our touring income. I've been fortunate to enjoy decent retainers/salaries over the years, but usually I work as a sub-contractor making a fixed amount per show + expenses.
Some gigs pay well, others are crap. I've seen guys playing for surprisingly little for certain 'veteran' acts, and some get paid more than I would have guessed! Same goes for new artists as well. There are no real rules, the AFM union live engagement scale is a joke and working conditions vary widely as well.
Next weekend, for example, I'll be hopping in an SUV with a small band playing for an indie artist playing 5 hours out-of-town and sharing a hotel room for a couple of bills.

But, in following weeks, I'll be on a plane with a signed act playing arenas opening for Taylor Swift & making more than double that playing only 4 songs a night, staying in nice hotels and not having to worry about gear, food or anything really.

Then, I immediately leave that tour to hop on a bus to tour Canada with a signed act for a month making great money!

It's always a mixed bag & every 'gig' is different with different compensation.
...Being a "band member" is an entirely different ball of yarn! As always, in business, with more risk comes more reward- so if you have ownership in the band & tour, you are always taking a risk. Even U2 lost money on a couple of world tours back in the late 80's!
Touring income, for a band member/owner, relies heavily on full concert attendance and merchandise sales. If either are weak, expect to
lose money. And it happens at every level, too! Even Rihanna had to cancel most of her 2011 dates. 2010 and 2011 have been the most challenging years for booking agents ever.
With this risk can come phenomenal reward, however. Guarantees for top-acts can reach over a million a show! (
Of course tour expenses come out of that, but still!) Acts doing clubs & small theaters can make a decent living, if they are smart. Even indie acts are doing ok these days. It's all about good tour planning and keeping overhead (busses, trucks, production) realistic.