Can the Flash Bomb upgrade pop leads

Yes, the second tower will accept the first as a sacrifice.

It becomes stronger based on the types of towers sacrificed. In the case you've given, it will only obtain stronger sunrays, (you have not given an image or description as to what other towers are there, so I assume these are the only towers to exist) because the other Temple is an upgraded super monkey.

This will actually make the tower weaker if the first tower had any sacrifices when it was built, which I would assume it did (unless you sold all of your towers to be able to afford the first upgrade).

The best source I've found is a forum post. Here's the content:

Dart monkey
0/0: 1 / 11
3/0: 18 / 28
3/1: 19 / 29
3/2: 21 / 31
4/0: 100 / 110
4/1: 101 / 111
4/2: 103 / 113
0/1: 2 / 12
0/2: 4 / 14
0/3: 4 x 3 = 12 / 14 x 3 = 42
Splodey Darts: +10 after dart pops.

Tack Shooter/Tack Awesomizer
0/0: 1 x 8 / 2 x 8 = 16
3/0: 1 x 16 / 2 x 16 = 32
4/0: 60 / 120 (A bug makes that 61 now)
0/3: 2 x 8 = 16 / 4 x 8 = 32
0/4: Infinity
Specialty/Tack Awesomizer
0/0: 2 x 8 = 16 / 3 x 8 = 24
3/0: 2 x 16 = 32 / 3 x 16 = 48
4/0: 61 / 122 (A bug makes that 62)
0/3: 3 x 8 = 24 / 6 x 8 = 48

Sniper Monkey/Rifle Range
0/0: 2 layers / 3 layers
1/0: 4 layers / 5 layers
2/0: 7 layers / 8 layers
3/0: 18 layers / 19 layers

Boomerang Thrower/Double Ranga
0/0: 3 / 3 x 2 = 6
1/0: 7 / 7 x 2 = 14
2/0: 12 / 12 x 2 = 24
3/0: 101 / 101 x 2 = 202
4/0: 10000 to orbiting glaives

Ninja Monkey
0/0: 2
2/0: 4
3/0: 4 x 2 = 8
4/0: 4 x 5 = 20
x/3: 30

Bomb Tower
0/0: 40
0/1: 50
2/0: 40 + 8 = 48
2/1: 50 + 8 = 58
3/0: 40 x 9 = 360
3/1: 50 x 9 = 450
0/3: 10 damage to blimps
0/4: 700 damage to blimps

Ice tower
0/0: 10000
0/3: 1 per shard
x/4: infinite

Glue Gunner
0/0: 1
x/2: 6
x/3: 12
x/4: infinite

Monkey Buccaneer
0/0: 5
0/1: 5 + 1 x 4 = 9
4/0: 5 x 8 + 5 x 2 for a plane = 50
0/3: 5 + 1 x 4 + 30 = 39

Monkey Ace
0/0: 15 x 8 = 120
2/0: 18 x 8 = 144
4/0: 18 + 40 = 58 for one
0/1: 40
0/3: 15 x 16 = 240
2/3: 18 x 16 = 288
0/4: infinite, 500 damage to blimps

Super Monkey
0/0: 1
1/0: 1 x 2
2/0: 3
3/0: 15 x 3 per frame
4/0: so big it's hard to find out
0/3: 3
1/3: 4
2/3: 5
0/4: 5
1/4: 6
2/4: 7
Ability: +250000

Monkey Apprentice
0/0: 2
1/0: 7
2/0: 7, 25
3/0: 7, 25, 20
4/0: 7, 25, 70
0/1: 40
0/3: 4 per frame
0/4: 2 per frame
Homing: 7
Tiny tornadoes: don't know, don't have this premium.

Village
4/0: 1 per frame, 2 layers per frame
0/1: grants +1 to all towers except sniper
0/4: doubles popping power for all towers except sniper

Mortar
0/0: 40
4/0: 100
ability: infinite

Dartling
0/0: 1
3/0: 13
4/0: 100
0/1: 3
3/1: 15
0/3: 40
0/4: 40 x 3 = 120
Ability: 500 x 40 = 2000

Spike Factory/Tack Awesomizer
0/0: 5 / 10
1/0: 10 / 20
3/0: 16 / 32
4/0: 16 + 20 / 32 + 40
0/3: 15 damage to MOABs
1/3: 30 damage to MOABs
0/4: 1000 / 2000
1/4: 2000 / 4000

Monkey Engineer
0/0: 3
Sentry: 2
3/0: need further tests
4/0: 250
0/1: 8

Bloonchipper
0/0: 250 RBE
4/0: 600 damage to blimps
0/3: 750 RBE

Levels are shown as left path/right path. In a number / number, the first number is the base number and the second number is with the appropriate premium or specialty building. For example, Tack Awesomizer doubles the pierce for Tack Shooters and doubles the spiking of Spike Factories.