Question about yeast and pitching temperatures
Hopefully I do not have too many Variables to get an idea about this.
All batches I have made so far have used Dry Ale yeast.
Most of the recipes have done said to pitch yeast when under 90F, so I have pitched at 85 to 89 with Muntons' Ale yeast.

However my latest batch of Brown Ale I used Safale s-04 and pitched at 70F
I have notice that the gas emanations coming from the airlock are not as fruity
and was wondering if this is due to temp or the yeast that was used.

It's a tough call, really. You can pitch the same yeast strain in the same temperature wort on the same day, and end up with different smelling fermentations. There's a lot going on in actively fermenting wort, and there is no standard smell you can expect from a given yeast strain. I've pitched Burton ale yeast several times, and the smells have ranged from sweet pears to putrid farts. The beers all came out good, though.
Having said all that, I would recommend that you wait to pitch any yeast until the wort is in the low to mid 70's at least. In my opinion, pitching at 85 to 90 degrees is way too high of a temp, and you could experience problems with many yeast strains (particularly S-04 and US-05) at that temp. If you have a fast start, then your fermenting wort might only have cooled to 80 degrees or so. Fermentation creates heat, so your wort might end up fermenting at around 88 or 90 degrees for the largest portion of your ferment. Even if it's only fermenting in the high 70s, you can expect some yeast strains to throw fusel alcohols at that temperature (US-05!).
Some brewing yeast strains can be fermented in the high 80s with little or no problems, but those are the exception to the rule. Most of the belgian yeasts can be fermented in these ranges.
Anyway, I know I haven't really answered your question, but it's really a tough question to answer, and a non-issue. The true test of a yeast is in the flavor of your beer, not the smell of the ferment. My suggestion....
RDWAHAHB!

I never pitch untill the wort is 28C or under (about 82 fahrenheit). However living where I do at times of the year the entire fermentation takes place at 78-79fahrenheit, and that's with wet towels and fans cooling down the fermenter. Sometimes you just have to make do with the temps you have.

Jb