I don't think we can look at ridership on this in the same context as commuters. Every induced personal tourism night for other Canadians is like the Alberta economy exporting two barrels of oil ($100 in Calgary, $120 in the Banff/Canmore). This average is held down by the sheer number of visiting and staying with friends and relatives.
Each international tourist is worth $1050 on average to Alberta (per night is more fuzzy at a quick look, so lets say $200 a night as we're assuming less friends and family accommodation).
If, pulling numbers from thin air, the train induced 1 extra night from just 100 people on an average day, with an average spend of $150, that equals to $5.5 million in extra tourism spending a year. Half of that spending is captured back by government as taxes (as it flows through the economy). I doubt the train would induce many entirely new outside of Alberta travellers to plan a trip, but who knows some people like riding trains, and people just need an excuse to choose somewhere, why not a new train in a national park of the original CPR route? Even just 5 people a day on average induced international travellers would be $2 million a year in tourism spending.